Activities to enhance learning Essay Example | Topics and Well Written Essays - 1500 words

Activities to enhance learning - Essay Example Technology can be used to enhance learning and education. Traditional classrooms are increasingly being replaced by virtual classrooms in the globalized education system. Some of the systems that can be used in the promotion of online learning include the use of the audience response systems and clickers. At the same time, advanced institutions are using simulation in the laboratories to prepare the students from the professional market experiences. Distance learning happens when the learner is separated from the teacher geographically and time-wise. According to instructional technology, distance learning is the process of extending resource sharing opportunities to other classrooms through the use of video and multimedia communications. This essay aims at having a creative look into the online activities that enhance student learning, assessment and engagement through critical thinking. These analytical suggestions can greatly improve the learning outcomes of the N534 course. The I nternet is one of the most important media when it comes to online learning environment and technology. Online learning especially in nursing is known to reduce time and space barriers in the process of learning. Online learning can be entirely electronic or a hybrid of learning environments. Hybrid learning tends to combine virtual learning strategies with face-to-face learning. The Internet is known to have introduced the concept of pluralisation of place. This means that persons and participate in multiple environments using a virtual atmosphere. In the case of online learning, the instructor is responsible for moderating and mentoring students. However, the students are expected to have a strong self-drive. The e-learning atmosphere is known to provide a platform for students’ discussions across the continents (Allen, 2007). Students in a nursing class can access online resources, share important documents through online applications and submit examination in the online c lassroom (Bonk & Zhang, 2008). Technology has allowed online students to interact with faculties and mentors. In the online learning environment, materials are presented through videotaping, audio taping, and links to websites. There are interactive websites designed to host online learning environments (Bonk & Zhang, 2008). In the case of learning environments, the interaction can be real-time, which is also known as synchronous, or asynchronous. Synchronous online interactions entail the use of chat room in the process of teaching (Allen, 2007). This involves typing. Asynchronous communication means leaving messages that others can read in their convenience (Shea-Schultz & Fogarty, 2002). In the online learning strategy, the entire programs and group courses are offered online. Online learners can attend virtual universities like California Virtual University. There are unique materials that serve as a means of promoting online learning and teaching. Successful learning must be as sessed on a regular basis. The method of learning has a great impact in the process of learning (Bonk & Zhang, 2008). The entire process and assessment of learning require substantial institutional and financial investment. Institutions must invest in faculty development, infrastructure, and equipment. Technology aided teaching strategies dramatically affect the way teaching and learning occurs. This challenges the traditional relationship between academic institutions and students. Students must be encouraged to participate in the learning process. This entails inviting them to speak in the classroom (Shea-Schultz & Fogarty, 2002). This learning strategy can have a profound effect if the teacher creates a safe environment for the students to learn. The teacher is expected to summarize discussion from time to time. This helps in highlighting key points and allows students to follow on the discussion (Allen, 2007). Th

Organizational Development Question # 2 Essay Example | Topics and Well Written Essays - 250 words

Organizational Development Question # 2 - Essay Example A well known and respected person makes good sales for the organization. This will intern improve the organization performance. In the case of a negative personality, the organization should in a way invest in changing the individual personality as it affects the performance of an organization. The organization may reward or appraise the individual performance in order change the personality of the employee. To improve an organization’s performance, employee characters ought to be well known by their managers(Robbins & Judge, 2011). One employee may be innovative while another is a good decision maker. As a manager, combining different characteristics of different employees and acting to the development of different ideas from the employees improves organizational performance(Robbins & Judge, 2011). Making the employees own the organization is a improving the performance of a firm as the works as if they are the owners of the organization. A manager recognizes their characteristics, perceptions and biases when they interact with their employees(Robbins & Judge, 2011). An employees ‘behavior may trigger a character in a manager. When an employee code of behaviors differs from that expected in an organization, the manager may develop perceptions towards the employee. As a manager, there is the need for better understanding of the employees and their behaviors in the organizat ion. A manager should react professionally towards a given situation and avoid personal reactions towards the employee(Robbins & Judge, 2011). Organization development as the huge efforts to increase the efficiency and effectiveness of an organization, should go hand in hand with the personality of employees in an organization.(Robbins & Judge, 2011) Different characteristics of employees in an organization may either improve or lead firm to solvency. Celebrities improves the

Swot Matrix for Compass Group Essay Example for Free

Swot Matrix for Compass Group Essay The SWOT analysis that my group and I came up with took a lot of time and research to ensure that our analysis would be effective. (SWOT analysis on page? ) Strengths Our group came up with five major strengths that Compass obtains. The first major strength that Compass possesses is they have excellent customer service. Excellent customer service is a major strength to have because this makes customers want to come back and this keeps revenue up. The second strength that is entailed on our SWOT analysis is strong client relationships. This is evident in their day to day activities while dealing customers and clients. The third strength Compass possessed is they have a very diversified client base. The fourth strength is convenience. I think that Compass Group biggest strengths are that they have a diversified client base and that they are what clients view as â€Å"convenient†. Because Compass has three divisions that are station around the world it can gain different clients and be able their needs. The next strength that is entailed on our SWOT analysis is Compass Group has consistent revenue growth. This is very important when dealing with any company because revenue is what pays the expenses to run the company and without revenue the company would go out of business. The last strength is Compass group’s diversified geographic presence. Compass Group has four divisions located in four different countries making it easier to target different client in different countries. Weakness Every company has weakness or things that can be better at and Compass is one of them companies. One of Compass Group’s weaknesses is that since they have divisions all over the world, not all of the managers operate the same way. This can be a problem because as a company, you want everybody to be on the same page even if you have different divisions operating out of different countries. The second weakness is that Compass Group trades in too many countries. It is economically not worth it. The third weakness is that Compass group leverage ratios show high debt. This means that Compass Group is operating it’s company at a high risk. The third weakness that Compass Group processes is that it has very low profitability ratios. The last weakness that is on the SWOT analysis is that Compass Group Time-Interest-Earned is very high. That means Compass has a lot of money that can be allocated for other purposes. Opportunities Just like every company has strengths and weakness, they also have opportunities to make their company better. The first opportunity is that restaurant industry sales have increased sixty-six percent in the U. S since 1970. The second opportunity is that fifty-two percent of meals are eaten outside of the home. What both of these stats tell me are that more people are going out to eat instead and getting a traditional home-cooked meal and this can only help my company become more profitable. The third opportunities we saw for Compass is that the contract food service market is still growing. This is great for Compass because this gives Compass an opportunity to gain more clients. Another opportunity for compass Group to grow as a company would be to seek the military as a client. Threats The threats to a company are the most important aspect of the SWOT analysis because a threat can cost a company money and it just might run you out of business. The first threat is that the sales /employee ratio is considerable lower than other industries. This could be a problem because as a company you are not getting enough sales per employee and you are losing money because of it. The second threat to Compass Group is that menu prices increased one-two percent with higher labor costs. This could be a big threat depending on the customers because there are always going to be one or two customers complaining about the new prices but it becomes a problem when a majority of you customers start complaining then you can lose of on business. The third threat is the compass Group rival competitors control seventy percent of the US contract food market. If this threat is not lowered to somewhere among fifty percent Compass Group could lose a lot of money in the near future, because if you rival competitors control more than half or the market they can dictate the price to the market. Then, Compass Group will have to make a choice if they want to continue with the own method or play copycat. The next threat of UN investigations can bring bad press to Compass Group and maybe lose some money too due to fines, court cost and things of that nature. The last threat is the never-ending problems of oil prices. This is not a huge problem for a big company like compass group but it is a problem because with rising oil prices it costs more to ship the necessary items to their destination.

There Are Serious Concerns Over Food Waste Environmental Sciences Essay

There Are Serious Concerns Over Food Waste Environmental Sciences Essay Food waste is a serious environmental, social and economic concern not only to United Kingdom but also to the whole world. Even though Food waste was recognized as a considerable problem, it was not identified as a serious concern to the environment till recently. Among environmentally significant activities, the production, trade, and consumption of food products have been identified as crucial contributors to numerous environmental problems One of the greatest threats of the century is Global Warming and Climate change. The need of the hour is to effectively tackle the climate change issue and GHG emission. According to Waste and resources action program (WRAP), about 20% of climate change emissions are related to the production, processing, transportation and storage of food. Agriculture contributes significantly to GHG emissions The domestic household in uk produces around 8,300,000 tons of food waste and is the single largest producer of food waste. Local authorities spend 1 billion pound a year disposing food waste. The foods we throw out to the landfill gets broken down to carbon dioxide and methane gas (green house gases) and are the prime reasons for global warming. If UK has to meet the international targets  on climate change and GHG emissions, it is important to reduce the amount of food waste going to the landfill. Spaces for land filling of wastes are rapidly diminishing, alongside European Union legislation that demands large amounts of waste be diverted from landfill over the next 15 years* Food waste puts a large burden on the finances of each household and  local councils in the UK; Local authorities spend 1 billion pound a year disposing food waste. Wasted food is estimated to cost each British household  £250- £400 per year,  accumulating to  £15,000- £24,000 over a lifetime.. Objectives and Methadology Love Food Hate Waste is a social campaign, launched by WRAP, in 2007,with the aim of reducing the amount of food waste in UK. The campaign is focused on raising consumer awareness about the various problems caused by food waste. WRAP calculated that preventing good food going to waste could reduce the annual emission of carbon dioxide by 18 million tones, the same effect as taking one in 5 cars off the road. Love Food Hate Waste campaign is supported by the government and is backed by celebrity chefs. Love food Hate waste also has a website which provides practical advice and tips on how to use most of the food they buy. The objective of the campaign is to raise awareness of easy, practical, everyday ways that households can reduce food waste. Everyone including local authorities, community groups, retailers, food manufactures and consumers are part of this campaign. For example, Resource Futures recruited and managed two embedded Outreach Workers to support the North London Waste Authoritys, WRAP funded, Love Food Hate Waste campaign. During the seven month period, the Outreach Workers organized and delivered over sixty road shows in supermarkets, businesses, libraries and at community groups, across NLWAs seven constituent boroughs, to engage more than 3,500 people with the campaign. It focuses on consumers strong desire to reduce wastefulness by sending positive messages about the rewards and benefits that can be achieved through specific behavioral change. The campaign benefits the consumer and the environment by reducing budgets and minimizing land fill and carbon emissions. Some of the methods which can be used to reduce waste in an house hold are: Reduce your proportion size: Love Food Hate Waste website has a tool to help you calculate appropriate portion sizes. The portion planner removes the guesswork by suggesting how much to cook, depending on whos coming for dinner, and ways to measure it Plan ahead: By planning the meal for a week and by shopping accordingly can save you a lot of money and prevents good food going to the waste bin. Tips on storage: Gives you easy tips on how to store things and encourage you to make effective use of fridge and freezers if necessary. Special Recipes: which makes use of use of all the odds and ends that invariably get leftover from previous meals or forgotten in the fruit bowl or the back of the fridge If nothing above works, recycling can be done. Composting is one good option. Only Those waste which nothing can be done is dumped in to landfill The Love food Hate waste Organize Door stepping campaigns providing information packs and Advice, targeted at reducing household waste. They also organize road shows, surveys and do advertising through radio and printed Medias. It owns a website love food hate waste.com where you can find many useful tips to reduce food waste. Analysis of the Sustainable Consumption approach One of the main cause for environmental degradation is the over consumption by the developed countries and a switch towards sustainable consumption pattern is very essential. The definition proposed by the 1994 Oslo Symposium on Sustainable Consumption defines it as the use of services and related products which respond to basic needs and bring a better quality of life while minimizing the use of natural resources and toxic materials as well as emissions of waste and pollutants over the life cycle of the service or product so as not to jeopardise the needs of future generations.  The two approaches towards sustainable consumption are the Main Stream approach and an alternative New Economics approach. The strategy of UK government in 2003 was continuous economic growth and social progress that respects the limits of earths eco systems to have a better quality of life. The concept of mainstream approach is of a strong stable and sustainable economy and include initiatives like   initiatives for product labeling, consumer education and environmental taxation. mainstream economics is deeply embedded in modernitys vision of progress and growth. The critics of this approach claims that this method is quite ineffective and doesnt address the fundamental problem of consumption. Based on several factors on the environment and society, the critics of main stream model proposed a new model collectively known as New Economics. They argue that economics cannot be separated from its understructures in environmental and social contexts. The Love food hate waste is one such campaign which follows the alternative approach of sustainable consumption. The diagram below shows how the campaigns approach towards sustainable consumption. ECO-EFFICIENCY more productive use of materials and energy Green growth Efficiency INCREASED . PRODUCT LIFE SPANS Sustainable Consumption Sufficiency SLOW CONSUMPTION reduced throughput of products and services Recession The campaign aims to reduce the amount of waste by consuming less by reducing your portion size and shopping less. In other words sufficiency is achieved by reduced consumption of products. The approach also defines green economics which means to increase the efficiency by more productive use of materials and energy. The model defines efficiency and sufficiency as the key towards sustainable consumption. The greater focus on sufficiency alone may lead to economic instability on a wider focus. Increased product life spans, may enable such problems to be overcome by providing for both efficiency and sufficiency. The efficiency can be increased by using the left overs and reusing and recycling. Theories Linked to LFHW Campaign. LFHW is basically a social marketing campaign aiming for a behavioral change by consuming more sensibly and thereby producing less waste. To understand the theories it is important to understand the driving forces to the same. Some of the forces influenced are: Knowledge, information, fashions beliefs (education, media, marketing) Price / affordabilit Tastes and Habits Demographic changes: ageing population, single person society, wealth Culture, social family expectations, norms, aspirations Availability Time and Season The campaign does its focus on the utilitarian theory and more importantly on social and psychological theories. The campaign targets the people who behave unsustainable because they lack information and help them to overcome the problems by rendering information to the needy. The utilitarian approach says that consumers seek to spend money on goods which gives greatest satisfaction or in other words consumers behave as utility maximizers. The LFHW campaign helps and encourage in cognitive thinking before you shop. It spread the importance of prior planning before shopping. By planning your meals for the whole week, you know what to buy and from where to buy. In the present scenario, people get tempted and buy things with offers like buy 1 get 1 free, even though they really dont need that. Its found that one in every 3 shopping bags goes directly to the waste bin. The campaign educates people how the value of food can be increased if the left over can be used to make new dishes. Human behavior is formed and routinized by social structure Apart from the conventionally acknowledged constraints like price and information, campaign also negotiates social, psychological and structural constraints. LFHW organizes public campaigns with celebrity chefs and attracts the whole society for a behavioral change. As a social marketing campaign, the main themes of the campaign are 4Es (Engage, Encourage, Enable and Exemplify). Engaging consumers and households to rethink their behavior is one of the main ways in which waste prevention can be progressed. Enabling households to take action or overcome barriers, through the provision of services like reduce reuse and recycling. Policy measures -Encouraging households to rethink their behavior so as to reduce their waste generation. The most frequently applied suite or package of waste prevention policy measures Appears to include most or all of the following activities. Collaboration between public, private and third sectors. Producer and responsibility. Variable rate charging (pay as you throw) systems (generally applied to householders residual waste). Public sector funding for pilot projects. Exemplified by means of monitoring and evaluation; Measuring and evaluation of waste prevention is challenging. The data collected should be true and of high quality. Some of the methods adopted are self-weighing Surveys done before and after the campaign, focusing on attitudes and behaviours and/or on participation rates Tracking the amount of waste from collection data and/or compositional nalysis estimation/modelling. Strength and weakness of Love food hate waste campaign Love food hate waste campaign claims that it has already prevented 1,37000 tonnes of waste goin to waste bin and   have helped close on two million households reduce their food waste, amounting to savings of almost  £300 million. A persons willingness to change along with action and appropriate policies from the local authorities is essential to bring a social change. The campaign is funded and supported by the governmentand almost every county council has given its support to the campaign. Retailers and food manufacturers also support to reduce food waste and they are the official sponsors of the campaign. Unlike Other campaigns, consumer is also economically benefited and hence more people are willing take part in the campaign. It also helps in reducing the so called Value Action Gap. The campaign is both focused at individual and social aspects and hence is more effective. a large body of studies asserts that personal factors are necessary and essential to foster behavioral changes, even though the correspondence between attitudinal variables and behavior is often moderate {reference*(2} The website lovefoodhatewaste.com gives you a lot of information and makes it easily accessible at any point of time. A lot of people gives their experience and valuable opinion which encourage other people to minimize waste. Some of the weaknesses of the campaign are: The campaign is too focused on using left overs and freezing, whereas shopping storage and portion control are effective strategies. The campaign deals with utilitarian concept and socio-psychological theories where as doesnt consider Infrastructure of provision approach. The campaign doesnt focus on the production part of food. food that goes to waste during Production and distribution accounts for 5 percentage of the GHG emissions. Globally 15-50% of food produced is wasted post harvest and no action is taken prevent those waste. The campaign is more concentrated on the food after consumption and doesnt look in to the broader aspects of food. Food has different utility and meanings when it comes to Entertainment, pleasure satisfaction, love status, comfort, time pass, bribery, religious significance, social glue, power, habbit, need, guilt, culture and so on. The amount of waste generated differs for each case and no effort has been taken to realy understand this complex system. Oxfordshire council-tax payers have saved over  £50,000 in waste disposal costs by throwing away less food since Oxfordshire Waste Partnership (OWP) launched its Love Food Hate Waste campaign last March Love Food Hate waste Campaign is still in its early stage and has long way to go. The measurement of success of the campaign can be found by looking the amount of waste reduced as a result of this campaign. In the very first year, the campaign is successful in reducing 1,37000 tones of household waste. The initial statistics of the campaign sounds too intresting and shows how successful it has been. The campaign is successful in attaining attention of the large public. Even though the results are impressive, when compared to the true scale of the problem, it is just a mere drop in the ocean. To address the big issue like climate change we need to do a lot more to reduce the amount of waste produced. Some of the limitations are Lack of interest of certain individuals can be setback to the campaign. Some people consider that the protection of environment is governments job and are not concerned about the same. Some people think that their contribution is just marginal and hence dont do anything. Reduction of waste is moreover a private thing and since its not public there is no social pressure to do it. The lack of strong policies is certainly a limitation to the campaign Measuring and monitoring is a tough task to perform. The reliability on survey is questioned. Conclusion The sustainable consumption doesnt always means consuming less but It certainly should in the case of developed countries and in underdeveloped countries sustainable consumption means consuming more. Thus the aim of sustainable consumption is a high quality of life for every one- brought about by everyone consuming in ways that reduce the impacts of production and consumption. (UNESCO) Some of the challenges in achieving sustainable consumption are: Reccomendations The amount of waste produced by the supermarkets should be controlled and policy should be made to publish the waste generated by the supermarkets. The Whole concept of supermarket should change. The people should make some list for shopping and hand it over to the shopkeeper/salesman so that he will hand over the things you need. By doing so you wont be tempted by the offers like buy one get one free. The online shopping should be encouraged by avoiding tax. Refrigerant leakage accounts for 30 percentage of supermarkets direct GGHG emissions.( Environment investigation agency 2010). There should be some measure to control this pollution. Government should make strong policies and should introduce certain limits to the amount of waste that can be produced by each house. The threshold can be based on the total number of people living in the house. The waste above threshold limit should be fined. à ¢Ã¢â€š ¬Ã‚ ¦ http://apps.oxfordshire.gov.uk 2) Promoting sustainable consumption: Determinants of green purchases by Swiss consumers Carmen Tanner1,*,   Sybille Wà ¶lfing Kast2 Article first published online: 12 SEP 2003 DOI:  10.1002/mar.10101

Change Management Essay -- GCSE Business Marketing Coursework

Change Management The world in which business operates is changing at a rapid pace. Developments in technology, communications and competition have forced businesses to update their work practices and become globally competitive. Pressures for change in business can arise internally, that is from staff or management observing current processes, or from external pressures like changes to government policies. There are several pressures currently affecting large organizations in Australia, they are changing markets, technological innovation, Total Quality Management, changes to the nature of industrial relations (where wages and working conditions can be negotiated with staff), flatter organisational structures, HR perspective and environmental issues. These pressures for change must be recognised by management and to effectively manage change, an organization's leaders must enact a change management process. Effective change management is a three-step process. Psychologist Kurt Lewin identified the first step as ‘Unfreezing the present situation’. The term unfreezing refers to the way in which management must prepare for the change and overcome any resistance that they may face. Resistance to change is human nature, as people are generally reluctant to move from a current, comfortable situation, but this resistance can be overcome using a variety of methods. These methods include communication, participation, support, negotiation, manipulation and threats, ranging from the least severe (communication), to the most severe (threats). The most effective strategy to unfreezing the present situation is to minimise resistance, through the use of open communication channels and participation with employees, without resorting to severe actions. Once resistance has been overcome and the organization is ready for the change, the next step is ‘Moving to the new state’. This step is the actual implementation of the change itself. New policies are communicated and procedures are re-evaluated. Once the change is implemented, management must work to ‘Refreeze in the new situation’. This final step is of upmost importance because it will ensure that staff does not drift off into old habits and revert to the old procedures. Management must work to offer support to staff and monitor the new situation and ensure that the process of change was an effective one. The issu... ...ries to determine whether international campaigns have been effective. Globalisation can have both positive and negative effects on the internal environment of business. External changes can include increased sales, productivity, market share and profit, but internal changes can have a much greater effect on the day-to-day running of the business and an unprepared manager is vulnerable to the negative effects of globalisation. A frequent area of change in the internal environment is the management (corporate) structure. A company expanding overseas requires more staff, and as such, more managers. It is a common occurrence for organizations to adopt a functional or divisional model with a very large horizontal structure. Divisions may be divided geographically, as departments in each country or continent. The management style is generally changed when an organization begins to deal with foreign customers. In an effort to appear polite, managers must be aware of local cultures and traditions when working with foreign employees. It may be necessary to use a different style when dealing with employees from other countries where the participative/consultative style is not appropriate.

Of Mice And Men :: essays research papers

Of Mice and Men is one of Steinbeck’s best novels. John Steinbeck, born in Salinas, CA he goes back to that setting for this novel. There are five to six characters that Steinbeck develops and opens up to the reader through the novel. Although George, Lennie, Crooks, Candy, and Curly’s wife all seek a place to belong and someone to love as a cure to there loneliness, all their dreams for a better future are destroyed in the novel. George and Lennie are an unlikely pair of friends who are introduced in the beginning. George is â€Å"small and quick, dark of face, with restless eyes and sharp, strong features.†(2) Lennie contradicts George because he is a â€Å"huge man, shapeless of face, with large pale eyes, with wide sloping shoulders, and he walked heavily.†(2) George is the more dominant of the two because Lennie is slow in the head. George and Lennie are different from the rest of the people in the same occupation because as Lennie said to George, â€Å"because I got you to look after me, and you got me to look after you, and that’s why.†(14) They are also different because as George said, â€Å"We got a future. We got somebody to talk to that gives a damn about us.†(14) They also share a common goal for their future together. They want to be able to live on there own and have a couple of acres so they can plant things and have animals. They are going to â€Å"live off the fatta the lan’.†(14) This single dream makes George and Lennie different from everyone else. Candy is a nice, old, handicapped man on the ranch. He lost his hand four years earlier in a farm machine while working. Candy overheard George and Lennie discussing about a small piece of land they would like to buy. Candy was compensated $250 for the lost of his hand and has a total of $350 he is willing to invest into the place with George and Lennie. Candy wants to get the place soon because he knows they are going to fire him sometime in the near future. When they fire him he will not have anyone or anything at all. Candy says, â€Å"When they can me here I just wisht somebody’d shoot me. But they won’t do nothing like that. I won’t have no place to go.†(60) So, Candy just wants to be needed and to always have a place to work at and George and Lennie are his way to achieve that goal.

Effect Of Annealing Time And Temperature Environmental Sciences Essay

introduced to depict the experimental semi log I-V curve informations from the thermionic emanation theory utilizing ideality equation the ideality factor N of the rectifying tube was calculated from the incline of the additive part of the semi log I-V curve. Using equation 3.22, the nothing biased barrier tallness was determined from the impregnation current that was obtained from the intercept of the excess plotted additive part with current axis at V=0. In Fig. 4.1 the logarithmic dependance of I with forward biased electromotive force is seen to widen over more than five order of magnitude leting ‘n ‘ to be easy deduced from the gradient. Any interfacial oxides layer ensuing from exposure of the semiconducting material surface to the ambiance between growing and metallization would hold the consequence of doing ideality factor a electromotive force dependent parametric quantity instead than a changeless ( Rhoderick and Williams, 1988 ) . The one-dimensionality observed in Fig. 4.1 clearly show that any bing interfacial bed must be undistinguished thickness and value for ‘n ‘ which was deduced from Fig. 4.1 being close to 1 indicated the cross barrier conveyance procedure in preponderantly via thermionic emanation. Harmonizing to Pattabi et Al. ( 2007 ) an ideality factor greater than integrity is by and large attributed to the presence of a bias dependent Schottky barrier tallness. Image forces, burrowing, g eneration-recombination, interface drosss and interfacial oxide bed are possible factors which could take to a higher ideality factor. The ideality factor represents a direct step of interface uniformity. The values for both Ns and are listed in Table 4.1 for junctions at assorted times after formation ( while at room temperature ) and in Table 4.2 for a sample which was subjected to a series of tempering interventions in vacuity at 150C0. In order to analyze the stableness of Au-CdTe contacts, the electrical features of a figure of samples were investigated as map of clip after fiction. Table 4.1 gives the information for one of these samples which was studied over a period of four hebdomads. Immediately after fiction it can be seen in Table 4.1 that the barrier height measured 0.88ev. After one hebdomad there was important decrease in the barrier height to 0.80ev as determined from I-V measurings and after two hebdomads at that place was a farther decrease in the barrier height to 0.68eV. At this phase in order to look into the stableness of the measuring system, these measurings were repeated on the following twenty-four hours and, as the Table 4.1 shows indistinguishable features were observed. This confirmed the dependability of the measuring. Subsequent measuring after three hebdomads and four hebdomads indicated a much more stable behaviour of the contact with the barrier height being mentioned in the part 0.67 – 0.68eV.As it was expected that these procedures could be speeded up by increasing the temperature, a figure of sample were studied after tempering or different lengths of clip at 150C & A ; deg ; . Typical sets of I-V consequence are presented in Table 4.2. For this sample ( 228F ) the initial barrier tallness was calculated to be 0.95eV although this is non a dependable value in the position of the initial value of the ideality factor being instead high ( at 1.02 ) . How of all time after the sample was annealed at 150C & A ; deg ; for merely ten proceedingss, there was a important betterment in the ideality factor ( to 1.1 ) and a significant decrease in the measured barrier tallness to 0.75eV. It appears from this that the consequence of a brief annealing intervention was similar to go forthing the sample for a hebdomad or two at room temperature. After the sample was annealed for a 2nd clip ( for 15 proceedingss ) there was further but smaller decrease in barrier tallne ss to 0.68eV and after a 3rd annealing period ( this clip for 20 proceedingss ) there was an even smaller decrease to 0.65eV. This tendency in behaviour due to tempering, with an initial rapid autumn in the barrier height being followed by lower alterations and greater stableness is clearly similar to that observed for sample 228A which remained at room temperature for four hebdomads. It was noted above that this behaviour must be due to chemical reaction or diffusion procedures in the part of the M/S interface. In order to supply farther information on the nature of the procedures involved, a 2nd Au contact was formed to try 228F after it had been annealed ( with its first contact in topographic point ) for a sum of 45 proceedingss are antecedently described. The features of this 2nd contact are included in Table 4.2. It is clear that the initial barrier height 0.66eV for this new contact is closer to the concluding ( station tempering ) value for the original contact instead so to the much higher initial ( brittle ) value. This suggests that the procedures which influence the barrier tallness may be due to some out-diffusion from the inside of the semiconducting material to its surface. Clearly they are non dependent on the presence of the gold bed although some interaction between the Au contact and the implicit in semiconducting material is expected to happen ( Dharmadasa et al. , 1989 ; Van Meirhaeghe et al. , 1991 ) .The consequence of farther tempering for up to 70 proceedingss is rec orded in Table 4.2. Merely little alterations in ideality factor and barrier tallness were observed, bespeaking rather stable behaviour for the new junction similar to that of the original junction after tempering. Although Au is a p-type dopant in CdTe, the informations in table 4.1 and 4.2 indicates that the alterations in interface features are non dependent on the presence of Au during the procedure of tempering. An alternate account is that there is an outward diffusion of Cd ( likewise taking to the coevals of acceptor provinces near-surface part ) .This reading of the consequences is entirely understanding with the decision reached by Dharmadasa et Al. ( 1994 ) on the consequence of chemical etch interventions. Those etchants which were found to go forth the surface rich in Cd tended to bring forth barrier highs greater than 0.9 electron volts while those go forthing the surface deficient in Cd produced barrier highs which were ~ 0.2eV lower, as found in the instance of the annealed samples studied in this undertaking. Therefore, it is clear that interface reaction lead to a significant alteration in the defect construction in the locality of the junction but farther work will be necessa ry to find the exact construction of the defects provinces which might be responsible for Fermi degree traping before and after the reaction and the associated decrease in barrier tallness. 5.2 Effect of ion plating technique In order to compare the consequence for Au contacts formed by ion-assisted manner with contacts produced by the usual vaporization process, a figure of samples were given two contacts ( one of each type ) . Fig. 4.2 gives the features for the normal Au contact and Fig. 4.3 gives the features for the ion-plated contact with 15 unsweet ion-etching clip. As expected, the I-V features in Fig. 4.2 are with ideality factor ‘n ‘ 1.2 and barrier tallness ( ) 0.90eV. As expected, the features in Fig. 4.2 are really similar to those shown in Fig. 4.1. However, for the ion-plated contact with 15 unsweet ion-etching clip there is a drastic alteration in both ideality factor ‘n ‘ and the barrier tallness ( ) was found to be 2.2 and 0.69 electron volts severally from I-V features shown in Fig. 4.3. This consequence suggests that a significant denseness of defects has been created below the Au contacts as a consequence of ion barrage of the surface during the plating procedu re. The presence of defects in the depletion part, moving as recombination centres, leads to an extra forward prejudice current constituent with an ideality factor of about 2 ( Shochley and Read, 1952 ) . However, the alteration in the behavior for the ion plated contact with 20 unsweet ion-etching clip is even more drastic than observed in Fig. 4.3. There is a greater addition in both frontward and change by reversal bias current with a really low barrier tallness of the order of 0.45 electron volt and N was determined to be 4.1 observed from features shown in Fig. 4.3. Fig. 4.4 shows the battier highs as a map of ideality factors for these ion plated Schottky rectifying tubes. As can be seen from Fig. 4.4, there is a additive relationship between the barrier tallness and ideality factor, with the barrier height going smaller as the ideality factor additions. Change in ideality factor indicates that current conveyance mechanisms other than thermionic emanation are present. As this value of N is significantly greater than 2, as would be expected for a bearer recombination mechanism, as discussed earlier, it seems likely that bearer tunneling may besides be playing a function ( Popovic, 1978 ) . These consequences indicate that the possible consequence of plasma-induced surface defects is that they contribute to the conduction of the contact by moving as fast recombination centres ( Ponon, 1985 ) and in add-on to burrowing procedure suggest that this might be a utile manner of farming low opposition ( ohmic ) junction utilizing a lower work map metal. 5.3 Effect of Doping The ideal I-V features of a Schottky rectifying tube exhibits exponential prejudice dependance as in equation 3.21 can be reduced to For V & A ; gt ; 3kT/q The magnitude of this impregnation current is governed by the effectual barrier height i.e. the difference between the conductivity set lower limit ( CBM ) at the surface of Au/n-CdTe and the Fermi degree of the metal ( Au ) . The value of the barrier tallness can be calculated from the measured impregnation current utilizing equation 3.22 Deviation from this ideal behavior can be seen on the exponentially determined I-V features for normal, low and to a great extent doped InSb substrate in Figures 4.6, 4.7 and 4.8 severally where important inclines are observed for the current under contrary prejudice. Those divergences are attributed to image force take downing ( IFL ) , recombination phenomena due to the presence of deep traps and the being of high electric field ( Martin, 1981 ) . The ideality factors ‘n ‘ and effectual barrier tallness were calculated from I-V features utilizing equation 3.23 and 3.24. The term effectual reflects the fact that the barrier tallness deduced from I-V measurings is lower than the value that should be obtained under inactive status i.e. without bearer injection, and includes the consequence of the image force take downing. Fig 4.11 shows a comparative position of I-V features for these three doped samples. After rating of I-V features, the values of the effectual barrier tallness and ideality factors for three wafers are shown in Table 4.4. A graph between barrier highs and ideality factors of three doped Au/n-CdTe Schottky rectifying tube is shown in Fig 4.9. A additive relationship between ideality factor and barrier tallness can be seen in Fig. 4.9 which is comparable to Fig.4.4. It has been demonstrated theoretically and by experimentation that the additive relationship between and ‘n ‘ can be attribute d to the sidelong inhomogeneties of the barrier tallness in Schottky rectifying tubes ( Koutsouras et al. , 2005 ) . The presence of traps besides modifies the incline of the forward current and at the same clip the value of the ideality factor, which is higher than integrity for both samples ( low and high doped sample ) . With increasing dopant concentration, the breadth of the depletion part W i.e. given by relation 3.11 i.e. at a given prejudice decreases taking to higher electric Fieldss at the interface. Low barrier or effectual barrier height instead than observed for the to a great extent doped sample ( 549E ) substrate. That is the ground for the higher swill under contrary prejudice for doped samples ( 549F, 549F ) . However, the enhanced recombination rate due to the presence of deep trap degrees besides contributes coevals and recombination consequence and can non be excluded. With heavier doping, increasing figure of new donor-type energy degrees are created underneath the conductivity set border. Under these fortunes, the givers are so near together that the giver degrees are no longer discrete and non-interacting energy degrees. These are instead debauched unifying together to make an dross bond, and doing band-gap narrowing ( BNG ) of the conductivity set. Obviously, the BNG is the highest near M/S interface, and the lowest in the majority. The effectual M/S barrier tallness is therefore reduced, as shown schematically in Fig 5.1. The crisp tip of the conductivity set border in contact with the metal is peculiarly lowered, and the new barrier tallness becomes, where is the Figure 5.1: Conventional diagram demoing the decrease of M/S barrier tallness due to band-gap narrowing. barrier tallness without BNG, and is the barrier tallness with BGN. However, a much more opposition arises from the CdTe/InSb junction. It has been shown that there is a possible barrier at this interface, associated with a conductivity set discontinuity of ~0.31 eV ( Van Welzenis and Ridley, 1984 ) . From a elaborate analysis of I-V features for gold-contacted devices with similar dimensions to those in present survey, effectual opposition value of ~100? have been deduced for the CdTe/InSb junction part ( Sands and Scott, 1995 ) . Harmonizing to the thermionic emanation theory, the contact electric resistance at the M/S contact depends merely on the effectual M/S barrier tallness, as given by ( Sze, 1982 ) ( 5.1 ) Where S is the contact country ; q, K and T are electronic charge, Boltzman invariable and temperature severally and is the Richardson invariable ( with a value of ~ 1.2 -105 Am-2T-2 for CdTe ) . is the opposition associated with the forepart metal/CdTe junction. Assuming RC & A ; lt ; 10? so ?C & A ; lt ; 0.1?cm2 and the corresponding upper bound for effectual barrier tallness is 0.38 electron volt. This is consistency with surveies of Al contacts on cleen vacuity cleaved surfaces of CdTe which yielded barrier highs of ~ 0.1 electron volt ( Patterson et al. , 1986 ) . About all the old probe emphasized tunneling as the primary mechanism for low contact electric resistance in n-CdTe. The present survey dose non govern out the importance of burrowing in making low contact electric resistance. However, it demonstrates that, depending on how much is lower than, thermionic emanation, instead than burrowing, may so be the primary cause for low contact electric resistance even in the tunnel contacts. If the surface intervention is really good, and the metal parametric quantity ( e.g. , metal thickness, metal deposition temperature, metal work map, metal combination, etc. ) are optimal, so may be significantly lower than. This, together with BGN and IFL can so play a important function for giving thermionic emanation based low contact electric resistance. 5.4 Decisions The undermentioned decisions can be reached from the surveies on the effects of tempering clip and temperature, ion plated technique and doping in scope of 2.5-1016-1-1019 cm?3 on I-V features of the Au/n-CdTe Schottky rectifying tubes. From Comparative survey of ion plated and doped samples of Au/n-CdTe Schottky rectifying tube, a additive relationship between the effectual barrier highs and ideality factors was found which shows that barrier tallness lessenings as ideality factor additions. As a consequence conduction additions. From which it can be concluded that: When n = 1 so all conveyance of negatron is from the top of the barrier and thermionic emanation current mechanism should be dominant. When 1 & A ; lt ; n & A ; lt ; 2, so burrowing current mechanism is dominant. When n = 2, so all conveyance is due to coevals and recombination current. When N & A ; gt ; 4 so there is non simple burrowing but step degree burrowing occurred. Gold contact formed to n-CdTe by vacuity vaporization output Schottky barriers with initial barrier tallness In surplus of 0.88eV. This reduced to 0.66-0.68 electron volt in a period of clip which is dependent on temperature. This decrease is found to be accompanied by a partial compensation of the sickly givers in the semiconducting material part near to the contact, a procedure which can be attributed to a discriminatory out diffusion of Cadmium from this part to the contact surface. It has been shown that the usage of simple vapour deposition on Au on n-type CdTe epilayers gave rectifying behavior with barrier tallness 0.9eV. A drastic alteration in barrier tallness was observed by the usage of ion-assisted plasma procedure, an ion etching clip of 20 sec to Au contact. This decrease in barrier tallness is attributed to the plasma- induced surface defects that contribute to the high conduction of the contact by moving as recombination centres along with multi measure degree burrowing centres. Consequence of doping in Au/n-CdTe Schottky rectifying tube shows that if n-CdTe is to a great extent doped with important conductivity set flexing near M/S interface, burrowing is possible through metal/CdTe contact. The semiconducting material part at the interface therefore becomes really thin leting an unhampered flow of negatrons via burrowing. But existent challenge to accomplishing low resistively contact by utilizing reasonably doped semiconducting materials. Many devices do so necessitate low electric resistance contacts without the load of heavy doping ( Noor Mohammad, 2004 ) Consequence of doping on I-V features of Au/n-CdTe shows that barrier breadth ( tungsten ) decreases with the increasing doping denseness in conformity with ( Eq.3.11 ) . The chief decision to be drawn from the comparative survey of I-V features of Au/n-CdTe Schottky rectifying tube, formed by the ion-plating procedure and doping consequence, leads to a much reduced contact opposition suggest that this might be a utile manner of farming stable and low opposition ( ohmic ) junction utilizing a lower work map metal ( e.g. , Al etc. ) suitable for thin movie MBE grown devices.