1. Document that explains the chosen concept to the animator 1

2. Intrinsic Semiconductors Any chemically pure semiconductor has properties which are characteristic of the material alone. Such a material is called an “intrinsic semiconductor.”In the intrinsic case, conduction band electrons can only have come from formerly occupied valence band levels, leaving holes behind them. Authors Anura.B.Kenkre Course Name: Semiconducting Properties of materials. 2

3. Learning Objectives After interacting with this Learning Object, the learner will be able to: Define an intrinsic semiconductor. Predict the effect of an increase in temperature on the current flowing through the circuit. 3

4. Definitions of the components/Keywords: 5 3 2 4 1 Any chemically pure semiconductor has properties which are characteristic of the material alone. Such a material is called an “intrinsic semiconductor.” 4

5. 5 IMPORTANT NOTE TO THE ANIMATOR: All the instructions/labels or anything WRITTEN in blue are CONTENT NOT TO BE DISPLAYED! All the instructions WRITTEN in black are CONTENT TO BE DISPLAYED! This is not applicable for images as there can be overlapping of these colours there. This should be followed for all the instructions,labels,etc… Kindly keep a note of this while displaying text in the animation.

6. Master layout or diagram Make a schematic diagram of the concept Explain to the animator about the beginning and ending of the process. Draw image big enough for explaining. In above image, identify and label different components of the process/phenomenon. (These are like characters in a film)‏ Illustrate the basic flow of action by using arrows. Use BOLD lines in the diagram, (minimum 2pts.)‏ In the slide after that, provide the definitions of ALL the labels used in the diagram 5 3 2 4 1 INSTRUCTIONS SLIDE 6

7. Master layout or diagram You may have multiple master layouts. –In this case, number the master layout. ( e.g. Master layout 1)‏ – Each Master layout should be followed by the stepwise description of the animation stages related to it. 5 3 2 4 1 INSTRUCTIONS SLIDE 7

8. T=0K T 1 =300K T 2 =500K (room Temperature) (~much above room temperature) Ge Master Layout 5 3 4 1 8 Fig1 Fig2 Fig3 INTERACTIVITY: Eg ammeter battery Germanium crystal This image is called the energy band diagram. thermometer Temperature options This is called the microscopic picture This is called the circuit. electrons Valence band Conduction band These are the names given to the violet and gray rectangles. Radio buttons mA Use this font for the display. this is the LED display for the ammeter. Ge 1.5V Ge 1.5V (Absolute zero) mA

9. Animation design Please see the design template provided in the next slide. This is a sample template, and you are free to change as per your design requirements. Try and recreate the sections/subsections as shown in the template. 1 5 2 4 3 9

10. Ge Credits 10 Eg Conduction band Valence band What will you learn Lets Learn!Definitions Test your understanding (questionnaire) ‏ Lets Sum up (summary ) ‏ Want to know more… (Further Reading) ‏ Microscopic view Ge Energy band diagram Circuit 1.5V T=0K T 1 =300K T 2 =500K (room Temperature) (~much above room temperature) mA Ge 1.5V (Absolute zero)

11. Explain the process 1 5 3 2 4 In this step, use an example to explain the concept. It can be an analogy, a scenario, or an action which explains this concept/process/topic Try to use examples from day-to-day life to make it more clear You have to describe what steps the animator should take to make your concept come alive as a series of moving images. Keep the examples simple to understand, and also to illustrate/animate. 11

12. Stepwise description of process The goal of the document is to provide instructions to an animator who is not a expert. You have to describe what steps the animator should take to make your concept come alive as a moving visualization. Use one slide per step. This will ensure clarity of the explanation. Add a image of the step in the box, and the details in the table below the box. You can use any images for reference, but mention about it's copyright status The animator will have to re-draw / re-create the drawings Add more slides as per the requirement of the animation 1 5 3 2 4 12

13. Step 1: 1 5 3 2 4 Refer to the master layout for the interactivity…given below are samples depicting the radio buttons just for your reference. Select a temperature 13 Instructions for the animator Instruction to the learner Results and Output Interactivity type (IO1/IO2..) ‏ Radio buttons Select a temperature Show a pop up near the thermometer asking the user to select a temperature. Depending upon the radio button selected go to slide 14,16and 18 respectively. If the user selects T=0,go to slide 14. If the user selects T 1 =300K go to slide 16. If the user selects T 2 =500K go to slide18. T=0K T 1 =300K T 2 =500K

14. Eg Ge 14 Conduction band Valence band Fill up this gray rectangle with the gray balls…The number of balls shown here need not be followed…and show the same effect as indicated for all of them…make sure that the labels of ‘valence band and conduction band do not overlap on the electrons. The total number of balls in this rectangle has to be same in slides 14,16 and 18. Valence band Covalent bonds EMPTY electrons Energy band diagram Microscopic view mA Display 0.00 here Ge Notice that the units are milliamperes (mA) Circuit 1.5V For the germanium crystal,give a mouse over of the following: Length=1 cm Width=1mm Thickness=1mm Redraw all the images..do not retain the company names,if any..

15. Step 2: 1 5 3 2 4 Refer to images on slide 14. Audio Narration (if any) ‏ Description of the action/ interactivity Absolute zero 15 Show the animation as shown on slide 14. Repeat the animation till the user selects another temperature.

16. Eg 16 Fig1 Fig2 Fig3 hole Conduction band Valence band Conduction band Valence band hole mA Fill up this gray rectangle with the gray balls…The number of balls shown here need not be followed…and show the effect as indicated for only those gray balls that are shown here..NOT FOR ALL OF THEM.. make sure that the labels of ‘valence band and conduction band do not overlap on the electrons. The total number of balls in this rectangle has to be same in slides 14,16 and 18. electron Thermal energy electron Display 3.3 here Note:the motion of electrons in Fig 1 and 2 should happen simultaneously..(It could happen a little late here due to limitations of powerpoint) hole Ge electron Ge Notice that the units are milliamperes (mA) 1.5V Ge For the germanium crystal,give a mouse over of the following: Length=1 cm Width=1mm Thickness=1mm Redraw all the images..do not retain the company names,if any..

17. Step 3: 1 5 3 2 4 Refer to images on slide 16. Audio Narration (if any) ‏ Description of the action/ interactivity Room temperature 17 Show the animation as shown on slide 16. And while you are showing the animation in Fig 1 and 2,display the reading in Fig3 simultaneously. Also,Include a minus sign on the electrons.It is not included here due to space constraints. Repeat the animation till the user selects another temperature.

18. Eg 18 Fig1 Fig2 Fig3 hole Conduction band Valence band Conduction band Valence band hole A Fill up this gray rectangle with the gray balls…The number of balls shown here need not be followed…and show the effect as indicated for only those gray balls that are shown here..NOT FOR ALL OF THEM.. make sure that the labels of ‘valence band and conduction band do not overlap on the electrons. The total number of balls in this rectangle has to be same in slides 14,16 and 18. Thermal energy electron Display 1.84 here Note:the motion of electrons in Fig 1 and 2 should happen simultaneously..(It could happen a little late here due to limitations of powerpoint) hole Ge hole electron Ge electron hole Notice that the units are Amperes(A) 1.5V Ge For the germanium crystal,give a mouse over of the following: Length=1 cm Width=1mm Thickness=1mm Redraw all the images..do not retain the company names,if any..

19. Step 9: 1 5 3 2 4 Refer to images on slide 18. Audio Narration (if any) ‏ Description of the action/ interactivity much above room temperature. 19 Show the animation as shown on slide 18. And while you are showing the animation in Fig 1 and 2,display the reading in Fig3 simultaneously Also,Include a minus sign on the electrons.It is not included here due to space constraints. Repeat the animation till the user selects another temperature.

20. Interactivity and Boundary limits In this section, you will add the ‘Interactivity’ options to the animation. Use the template in the next slide to give the details. Insert the image of the step/s (explained earlier in the Section 3) in the box, and provide the details in the table below. The details of Interactivity could be: Types: Drop down, Slider bar, Data inputs etc. Options: Select one, Multiple selections etc Boundary Limits: Values of the parameters, which won’t show results after a particular point Results: Explain the effect of the interaction in this column Add more slides if necessary 1 2 5 3 4 20

21. 1 5 3 2 4 Refer to slides 13 to 19. Instructions for the animator Instruction to the learner Results and Output Boundary limits Interactivity type (IO1/IO2..) ‏ Interactivity option 1: Step No: 21

22. INSTRUCTIONS SLIDE Self- Assessment Questionnaire for Learners Please provide a set of questions that a user can answer based on the LO. They can be of the following types: –These questions should be 5 in number and can be of objective type (like MCQ, Match the columns, Yes or No, Sequencing, Odd One Out). –The questions can also be open-ended. The user would be asked to think about the question. The author is requested to provide hints if possible, but a full answer is not necessary. –One can include questions, for which the user will need to interact with the LO (with certain parameters) in order to answer it. 22

23. INSTRUCTIONS SLIDE Please make sure that the questions can be answered by interacting with the LO. It is better to avoid questions based purely on recall. Questionnaire for users to test their understanding 23

24. 24 Questionnaire 1. What is the difference in the energy band diagrams for room temperature and at a temperature much above room temperature? Answers: a)At room temperature, lesser number of electrons are excited to the conduction band as compared to much above room temperature b) At room temperature, more number of electrons are excited to the conduction band as compared to much above room temperature c) there is no difference in diagrams at different temperatures d)electrons are not excited to the conduction band at room temperature but they start getting excited at temperatures much above room temperature. Answers:1)a Feedback: If user clicks correct answer then display “Correct! Make sure you can explain the reasoning!” If user clicks incorrect answer then display “Have a look at the simulation and Try again!”

25. 25 Questionnaire 2. Why is there more current at higher temperatures? Answers: a)more number of electrons in the valence band b)lesser number of electrons getting excited from the valence band to the conduction band c)more number of electrons getting excited from the valence band to the conduction band d) ‏ cannot say. Answers:2)c Feedback: If user clicks correct answer then display “Correct! Make sure you can explain the reasoning!” If user clicks incorrect answer then display “Have a look at the simulation and Try again!”

26. 26 Questionnaire 3. The fact there are more number of electrons in the conduction band at higher temperatures is due to which of the following reasons? Answers: a)the crystal contains more number of electrons at higher temperatures b)as the temperature is raised, there exists more energy which causes more number of electrons to get excited c)Both a and b. d) ‏ At higher temperatures, there exist collisions between the electrons, which causes more number of electrons to get excited to the conduction band. Answers:3)b Feedback: If user clicks correct answer then display “Correct! Make sure you can explain the reasoning!” If user clicks incorrect answer then display “Have a look at the simulation and Try again!”

27. 27 Questionnaire 4. Why are Si and Ge called ‘ INTRINSIC ’ Semiconductors?? Answers: a)Since they conduct electricity at room temperatures b)Since they do not conduct electricity at absolute zero c)Both a and b. d) ‏ Since they are chemically pure and have properties which are characteristic of the material alone. Answers:4)d Feedback: If user clicks correct answer then display “Correct! Make sure you can explain the reasoning!” If user clicks incorrect answer then display “Have a look at the simulation and Try again!”

28. 28 Open ended questions: 1.What happens when more number of electrons are excited from the valence band to the conduction band at higher temperatures? 2.What do think happens to the electrons and holes in the valence band once any electron gets excited from the valence band to the conduction band?? (Hint1:Watch the animation on ‘Conductivity in Intrinsic Semiconductors’ to get an idea… Hint2:Watch the animation on Hole current to get an idea…) (Note to the animator:Show hint1 for question1 and hint 2 for question 2.Show these as clickable buttons next to the question so that when the user clicks on it,she will be able to view it..)This note is for the reference of the animator and it is not to be shown on screen.

29. Links for further reading Books: 1)Solid state physics-MA Wahab.(chapter 13) 2)Solid state physics-Ashcroft/Mermin. (Chapter 28) 3)Introduction to modern physics- Richtmyer, Kennard, Cooper.(Chapter 23) 29

30. INSTRUCTIONS SLIDE Please provide points to remember to understand the concept/ key terms of the animation The summary will help the user in the quick review of the concept. Summary 30

31. Summary Any chemically pure semiconductor has properties which are characteristic of the material alone. Such a material is called an “intrinsic semiconductor.” More number of electrons get excited to the conduction band at higher temperatures and hence more current flows through the circuit. 31