PhET-Simulations-for-Physics/C3/Semiconductors/English - Revision history

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Vidhithakur at 03:30, 17 December 2022

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Vidhithakur: Created page with "'''Semiconductors''' '''Author: Vidhi Thakur''' '''Keywords: PhET simulation''', dopants, diode, valence band, conduction band, donor, acceptor, depletion region '''video..."

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Created page with "'''Semiconductors''' '''Author: Vidhi Thakur''' '''Keywords: PhET simulation''', dopants, diode, valence band, conduction band, donor, acceptor, depletion region '''video..."

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'''Semiconductors'''

'''Author: Vidhi Thakur'''

'''Keywords: PhET simulation''', dopants, diode, valence band, conduction band, donor, acceptor, depletion region '''video tutorial.'''

{|border=1
|-
||'''Visual Cue'''
||''' Narration '''
|-
|| '''Slide Number 1'''

'''Title Slide'''
|| Welcome to this spoken tutorial on '''Semiconductors'''.
|-
|| '''Slide Number 2'''

'''Learning Objectives'''

|| In this tutorial, we will learn,

* How a battery acts as a driving force in a circuit.
* To add dopants to move the electrons in the circuit.
* How the dopants change energy levels in a semiconductor
* Why a pn junction acts as a diode
* Why a depletion region does not allow current to flow.

|-
|| '''Slide Number 3'''

'''System Requirement'''
|| Here I am using

'''Windows 11 (64 bit).'''

'''Java Version 1.8'''
|-
||'''Slide Number 4'''

'''Pre-requisites'''
'''https://spoken-tutorial.org'''
||To follow this tutorial the learner should be familiar with topics in high school science.
Please use the link below to access the tutorials on PhET simulations.
|-
||'''Slide Number 5'''

'''Link for PhET simulation'''

point to

'''https://phet.colorado.edu/en/simulations/conductivity/about'''
|| Please use the given link to download the PhET simulation.

'''https://phet.colorado.edu/en/simulations/semiconductor/about'''
|-
||'''Point to the file in the Downloads folder'''.
|| I have downloaded the '''Semiconductors simulation '''to my '''Downloads''' folder.
|-
||'''Double click the file to open'''
|| To open the simulation double click on the file.

|-
||'''Cursor on the interface.'''
|| This is the interface of '''Semiconductors simulation.'''
|-
||Cursor on '''main panel'''.

Cursor on '''input box.'''

Cursor on '''electrons.'''

|| The main panel consists of a circuit.

The circuit has a battery with the box to input the voltage.

'''Electrons''' are represented as blue spheres in the circuit.
|-
|| Cursor on '''dopants.'''

|| Point to the P Type and N Type dopants at the bottom.
A dopant is an impurity added to semiconductors to modify their conductivity.

At the bottom right P-type dopant is represented as '''red''' spheres and N-type as '''green''' spheres.

A P Type dopant is represented as '''red''' spheres and N Type as '''green''' spheres.

P-type dopant is with more holes, whereas n-type dopant is with more electrons.

|-
|| Cursor on '''dopant.'''

Cursor on '''valence band.'''
|| An electrode is connected to each dopant.

It expands into bands represented as '''yellow rectangles''' on the left panel.

The low energy band is the''' valence''' band.

It is filled with blue spheres as electrons and plus signs as holes.

|-
||

Cursor on '''conduction''' band.
|| The high energy band is the '''conduction''' band.

In semiconductors the gap between the bands is small.

'''Internal force '''arrow gives us the direction of the internal force.

'''Battery force '''arrow''' '''gives us the direction of battery force.
|-
|| Cursor on right panel.

Point to '''one(1) '''Segment.

'''Two(2)''' Segments.

|| On the right panel the '''Segments''' section is present.

It consists of one and two as options.

The''' one(1) '''Segment provides space for one dopant only.

The '''two(2)''' Segments provide space for two segments.

|-
|| Click on segment '''one'''.

Cursor on bands.

|| Let us first select segment one(1).

Here only one segment is present.

The electrode attached to the dopant expands into bands with electrons and holes.

Lower energy band is the valence band with low energy.

The higher energy band is the conduction band with high energy.

|-
|| Drag and add '''P-type''' in space in the bottom of the circuit.

Click on the up arrow till '''4V'''.

Cursor on circuit diagram.
|| Let’s drag and place a '''P-type '''dopant to fill in the purple space in the circuit.

Increase the voltage to '''4 volts''' and observe the movement of electrons in the circuit.

Current flows in the circuit with low energy from left-right.
|-
|| Click on down arrow till '''-4V.'''
|| Now let us decrease the voltage to''' -4 volts'''.

This way we change the terminals of the battery in the opposite direction.

There is a flow of current in the right-left direction in the circuit.

Changing the terminals, changes the direction of potential difference.

Hence direction of flow of current changes.

|-
|| Click on '''Clear Dopants'''.

Drag and add '''N-type''' dopant and click up arrow till 4V.

|| Let us clear dopants now.

Add N-type dopant to the space and increase the voltage to '''4 volts'''.

Since N-type dopants have more electrons they are known as '''donors'''.

The flow of current is from left to right in the conduction band at high energy.

|-
||

Click the down arrow till -4V.

||

Now let us change the voltage to''' -4 ''', that is. change the terminal of the battery.

This time flow of current is in the right-left''' '''direction

in the conduction band.

|-
|| Click on '''two''' segment.

Drag and add '''P-type''' dopant in the left space.

Click the arrow till 4V.

Cursor on internal force and battery force.
|| Now let us select Segments '''two(2)'''.

Drag and add '''P-type''' dopant in the left space and increase the voltage to 4 volts.

Note that electrons and holes in the valence band of the left segment disappear.

This is because p-type dopant is an acceptor.

Internal force is zero and battery force is from left to right.

So, there is no flow of current in the circuit.

|-
|| Drag and add an '''N-type''' dopant in the right space.

Cursor on battery.

|| Let us drag and add an N-type dopant in the right space.

Such diode formation is known as '''pn''' junction diode.

Here the positive terminal of the battery is connected to N-type.

Negative terminal is connected to the P-type.

Such arrangement is known as '''reversed bias.'''

|-
|| Cursor on valence band and conduction band.
|| Empty space is filled by electrons in the '''P-type''' dopant.

And holes occupy the conduction band of '''N-type''' dopant.

The direction of internal force, and battery force, are in the same''' '''direction.

Hence a more resistive thicker '''depletion''' region is formed.

This is due to the diffusion of carriers across the junction of the pn diode.

So, no flow of current is observed.

|-
|| Click on down arrow till '''-4V'''.

Cursor on battery and internal force.

Cursor on battery.
|| Now let us slowly change the voltage to '''-4 Volts'''.

Notice that decrease in voltage decreases the size of the battery force arrow.

At -4 Volts the battery force changes the direction and internal force becomes zero.

At -4 Volts, P-type dopant is connected to the positive terminal and vice-versa.

Hence it is '''forward biased''', so the depletion region is thinner here.

So, current flow is seen from N-type to P-type '''dopant '''in''' '''right-left direction.

|-
|| Click on '''Clear Dopants'''.

Drag and add '''N-type''' dopant in left space and click up arrow till 4V.

Cursor on battery and internal force.
|| Now let”s clear the '''dopants'''.

Drag and add '''N-type''' dopant in the left space and increase the voltage to '''4 Volts'''.

Electrons and holes are visible in the left segment as N-type dopants are donors.

'''Internal''' '''force''' is zero and battery force is in the right direction.

So, there is no flow of current,''' '''

|-
|| Drag and add a P-type dopant in the right space.

Cursor on battery

|| Let us drag and add '''P-type '''dopant in the right segment.

Such diode formation is known as '''pn junction diode'''.

Here, positive terminal is connected to P-type and negative terminal to N-type.

Such an arrangement is known as''' forward bias.'''

Flow of current is seen from N-type to P-type dopant from left to right direction.

Battery force is also in the same direction.
|-
|| Click on down arrow till '''-4V'''.

|| I will now change the voltage to''' -4 Volts'''.

The electrons in the left segment of the conduction band disappear.

Only holes are left.

Internal force and battery force are in the left direction.

So, we see no flow of current.

|-
|| '''Slide Number 11'''

'''Summary'''
|| With this we come to the end of this tutorial.

Let's summarise.

In this tutorial we have learnt,* How a battery acts as a driving force in a circuit.
* To add dopants to move the electrons in the circuit.
* How the dopants change energy levels in a semiconductor
* Why a pn junction acts as a diode
* Why a depletion region does not allow current to flow.

|-
|| '''Slide Number 12'''

'''Assignment'''
||

As an assignment,

Make various combinations of dopants at different voltages and record the observations.

|-
|| '''Slide''': 13

'''About Spoken Tutorial Project '''
||The video at the following link summarizes the Spoken Tutorial project.
* Please download and watch it.

|-
|| '''Slide''': 14

'''Spoken tutorial workshops '''
||We conduct workshops using spoken tutorials and give certificates.
* For more details, please contact us.

|-
|| '''Slide''': 15

'''Answers for THIS Spoken Tutorial '''

Do you have questions in THIS Spoken Tutorial?

Please visit this site

Choose the minute and second where you have the question.

Explain your question briefly

The spoken tutorial project will ensure answer.

You will have to register on this website to ask questions.
|| * <div style="margin-left:1.245cm;margin-right:0cm;">Please post your timed queries in this forum.

|-
|| '''Slide''': 17

'''Forum '''
||The Spoken Tutorial forum is for specific questions on this tutorial.
* Please do not post unrelated and general questions on them.
* This will help reduce the clutter.
* With less clutter, we can use these discussions as instructional material.

|-
|| '''Slide''': 16

'''Acknowledgement '''
|| Spoken Tutorial project is funded by the Ministry of Education (MoE), Govt. of India
|-
||
||This is Vidhi Thakur, a FOSSEE
* summer fellow 2022, IIT Bombay
* signing off

Thank you for joining.
|-
|}

<div style="margin-left:0.811cm;margin-right:0cm;">

@@ Line 1: / Line 1: @@
 '''Semiconductors'''
 '''Author: Vidhi Thakur'''
 '''Keywords: PhET simulation''', dopants, diode, valence band, conduction band, donor, acceptor, depletion region '''video tutorial.'''
@@ Line 26: / Line 24: @@
 * How a battery acts as a driving force in a circuit.
 * To add dopants to move the electrons in the circuit.
-* How the dopants change energy levels in a semiconductor
+* How the dopants change energy levels in a semiconductor.
-* Why a pn junction acts as a diode
-* Why a depletion region does not allow current to flow.
 |-
 || '''Slide Number 3'''
 '''System Requirement'''
-|| Here I am using
+|| Here I am using,
 * '''Windows 11 (64 bit)'''.
-* '''Java Version 1.8'''.
+* '''Java version 1.8'''.
 |-
-||'''Slide Number 4'''
+||'''Slide Number 5'''
 '''Pre-requisites'''
@@ Line 47: / Line 53: @@
 Please use the link below to access the tutorials on PhET simulations.
 |-
-||'''Slide Number 5'''
+||'''Slide Number 6'''
 '''Link for PhET simulation''' point to
@@ Line 101: / Line 107: @@
-The low energy band is the ''' valence''' band.
+The low energy band is the '''valence''' band.
@@ Line 114: / Line 120: @@
-'''Internal force ''' arrow gives us the direction of the internal force.
+'''Internal force''' arrow gives us the direction of the internal force.
@@ Line 132: / Line 138: @@
-The ''' one(1) '''segment provides space for one dopant only.
+The ''' one(1)''' segment provides space for one dopant only.
 The '''two(2)''' segments provide space for two dopants.
@@ Line 158: / Line 164: @@
 Cursor on circuit diagram.
-|| Let’s drag and place a '''P-type '''dopant to fill in the purple space in the circuit.
+|| Let’s drag and place a '''P-type ''' dopant to fill in the purple space in the circuit.
@@ Line 164: / Line 170: @@
-Current flows in the circuit with low energy from left-right.
+Current flows in the circuit with low energy from left to right.
 |-
 || Click on down arrow till '''-4V.'''
@@ Line 183: / Line 189: @@
 |-
 || Click on '''Clear Dopants'''.
-|| Let us clear dopants.
+|| Let us clear the dopants.
 |-
 ||Drag and add '''N-type''' dopant and click up arrow till 4V.
@@ Line 197: / Line 203: @@
 |-
 || Click the down arrow till -4V.
-|| Now let us change the voltage to ''' -4 ''', that is. change the terminal of the battery.
+|| Now let us change the voltage to ''' -4 ''', that is, change the terminal of the battery.
-This time flow of current is in the right-left direction in the '''conduction''' band.
+This time flow of current is in the right to left direction in the '''conduction''' band.
 |-
@@ Line 238: / Line 244: @@
-Such arrangement is known as '''reversed bias.'''
+Such arrangement is known as '''reversed bias'''.
 |-
@@ Line 281: / Line 287: @@
-So, current flow is seen from '''N-type''' to '''P-type '''dopant in right to left direction.
+So, current flow is seen from '''N-type''' to '''P-type ''' dopant in right to left direction.
 |-
@@ Line 339: / Line 345: @@
 |-
-|| '''Slide Number 6'''
+|| '''Slide Number 7'''
 '''Summary'''
@@ Line 350: / Line 356: @@
 * How a battery acts as a driving force in a circuit.
 * To add dopants to move the electrons in the circuit.
-* How the dopants change energy levels in a semiconductor
+* How the dopants change energy levels in a semiconductor.
 * Why a pn junction acts as a diode
 * Why a depletion region does not allow current to flow.
 |-
-|| '''Slide Number 7'''
+|| '''Slide Number 9'''
 '''Assignment'''
@@ Line 363: / Line 377: @@
 |-
-|| '''Slide Number 8'''
+|| '''Slide Number 10'''
 '''About Spoken Tutorial Project '''
@@ Line 371: / Line 385: @@
 |-
-|| '''Slide Number 9'''
+|| '''Slide Number 11'''
 '''Spoken tutorial workshops '''
@@ Line 379: / Line 393: @@
 |-
-|| '''Slide Number 10'''
+|| '''Slide Number 12'''
 '''Answers for THIS Spoken Tutorial '''
@@ Line 385: / Line 399: @@
 |-
-|| '''Slide Number 12'''
+|| '''Slide Number 13'''
 '''Acknowledgement '''
 || Spoken Tutorial project is funded by the Ministry of Education (MoE), Govt. of India
 |-
-||
+||  '''Slide Number 14'''
-||This is Vidhi Thakur, a FOSSEE summer fellow 2022, IIT Bombay signing off.
 Thank you for joining.
 |-
 |}

@@ Line 36: / Line 36: @@
 || Here I am using
-*'''Windows 11 (64 bit)'''.
+* '''Windows 11 (64 bit)'''.
-*'''Java Version 1.8'''.
+* '''Java Version 1.8'''.
 |-
 ||'''Slide Number 4'''
@@ Line 87: / Line 87: @@
 |-
 ||Point to the P Type and N Type dopants at the bottom.
-||A '''P-Type''' dopant is represented as red spheres and '''N-Type''' as green spheres..
+||A '''P-Type''' dopant is represented as red spheres and '''N-Type''' as green spheres.
-−
 '''P-type''' dopant is with more holes, whereas '''N-type''' dopant is with more electrons.
@@ Line 139: / Line 138: @@
 |-
 || Click on segment '''one'''.
 || Let us first select segment one(1).
@@ Line 160: / Line 156: @@
 Click on the up arrow till '''4V'''.
 Cursor on circuit diagram.
@@ Line 174: / Line 167: @@
 |-
 || Click on down arrow till '''-4V.'''
-|| Now let us decrease the voltage to''' -4 volts'''.
+|| Now let us decrease the voltage to ''' -4 volts'''.
@@ Line 180: / Line 173: @@
-There is a flow of current in the right-left direction in the circuit.
+There is a flow of current in the right to left direction in the circuit.
@@ Line 190: / Line 183: @@
 |-
 || Click on '''Clear Dopants'''.
-|| Let us clear dopants now.
+|| Let us clear dopants.
 |-
 ||Drag and add '''N-type''' dopant and click up arrow till 4V.
 ||Add '''N-type''' dopant to the space and increase the voltage to '''4 volts'''.
@@ Line 206: / Line 197: @@
 |-
 || Click the down arrow till -4V.
-|| Now let us change the voltage to''' -4 ''', that is. change the terminal of the battery.
+|| Now let us change the voltage to ''' -4 ''', that is. change the terminal of the battery.
@@ Line 218: / Line 209: @@
 Click the arrow till 4V.
@@ Line 230: / Line 220: @@
 |-
 ||Cursor on internal force and battery force.
 ||Internal force is zero and battery force is from left to right.
@@ Line 245: / Line 233: @@
 |-
 ||Cursor on battery.
-||Here the positive terminal of the battery is connected to '''N-type.'''
+||Here the positive terminal of the battery is connected to '''N-type'''.
 Negative terminal is connected to the '''P-type'''.
@@ Line 293: / Line 281: @@
-So, current flow is seen from '''N-type''' to '''P-type '''dopant in right-left direction.
+So, current flow is seen from '''N-type''' to '''P-type '''dopant in right to left direction.
 |-
@@ Line 301: / Line 289: @@
 Drag and add '''N-type''' dopant in left space and click up arrow till 4V.
-|| Now let”s clear the '''dopants'''.
+|| Now let's clear the '''dopants'''.
@@ Line 321: / Line 309: @@
 Cursor on battery
-| Let us drag and add '''P-type '''dopant in the right segment.
+|| Let us drag and add '''P-type '''dopant in the right segment.
@@ Line 330: / Line 318: @@
-Such an arrangement is known as''' forward bias.'''
+Such an arrangement is known as ''' forward bias.'''
@@ Line 339: / Line 327: @@
 |-
 || Click on down arrow till '''-4V'''.
-|| I will now change the voltage to''' -4 Volts'''.
+|| I will now change the voltage to ''' -4 Volts'''.

@@ Line 44: / Line 44: @@
 '''https://spoken-tutorial.org'''
 ||To follow this tutorial the learner should be familiar with topics in high school science.
 Please use the link below to access the tutorials on PhET simulations.
 |-
@@ Line 64: / Line 65: @@
 |-
 ||'''Cursor on the interface.'''
-|| This is the interface of '''Semiconductors simulation.'''
+|| This is the interface of '''Semiconductors simulation'''.
 |-
 ||Cursor on '''main panel'''.
@@ Line 80: / Line 81: @@
 |-
 || Cursor on '''dopants.'''
 || Two blank spaces are provided in the circuit to add two dopants.
@@ Line 90: / Line 87: @@
 |-
 ||Point to the P Type and N Type dopants at the bottom.
-||At the bottom right '''P-type''' dopant is represented as red spheres and '''N-type''' as green spheres.
+||A '''P-Type''' dopant is represented as red spheres and '''N-Type''' as green spheres..
-−
-−
 A '''P-Type''' dopant is represented as red spheres and '''N-Type''' as green spheres..
@@ Line 108: / Line 102: @@
-The low energy band is the''' valence''' band.
+The low energy band is the ''' valence''' band.
@@ Line 114: / Line 108: @@
 |-
-||
+|| Cursor on '''conduction''' band.
-−
 Cursor on '''conduction''' band.
 || The high energy band is the '''conduction''' band.
@@ Line 123: / Line 115: @@
-'''Internal force '''arrow gives us the direction of the internal force.
+'''Internal force ''' arrow gives us the direction of the internal force.
-'''Battery force '''arrow gives us the direction of battery force.
+'''Battery force '''  arrow gives us the direction of battery force.
 |-
 || Cursor on right panel.
@@ Line 141: / Line 133: @@
-The''' one(1) '''segment provides space for one dopant only.
+The ''' one(1) '''segment provides space for one dopant only.
 The '''two(2)''' segments provide space for two dopants.
@@ Line 213: / Line 205: @@
 |-
-||
+|| Click the down arrow till -4V.
-−
 Click the down arrow till -4V.
-−
-−
-−
-−
-−
-−
 || Now let us change the voltage to''' -4 ''', that is. change the terminal of the battery.
@@ Line 254: / Line 238: @@
 |-
 || Drag and add an '''N-type''' dopant in the right space.
 || Let us drag and add an '''N-type''' dopant in the right space.
@@ Line 264: / Line 245: @@
 |-
 ||Cursor on battery.
 ||Here the positive terminal of the battery is connected to '''N-type.'''
@@ Line 321: / Line 300: @@
 Drag and add '''N-type''' dopant in left space and click up arrow till 4V.
 || Now let”s clear the '''dopants'''.
@@ Line 348: / Line 321: @@
 Cursor on battery
 | Let us drag and add '''P-type '''dopant in the right segment.
-−
-−
-|| Let us drag and add '''P-type '''dopant in the right segment.
@@ Line 369: / Line 339: @@
 |-
 || Click on down arrow till '''-4V'''.
 || I will now change the voltage to''' -4 Volts'''.
@@ Line 378: / Line 345: @@
 Only holes are left.
 Internal force and battery force are in the left direction.
@@ Line 405: / Line 370: @@
 '''Assignment'''
-||
+|| As an assignment,
-As an assignment,
+* Make various combinations of dopants at different voltages and record the observations.
-−
 *Make various combinations of dopants at different voltages and record the observations.
 |-
@@ Line 416: / Line 379: @@
 '''About Spoken Tutorial Project '''
 ||The video at the following link summarizes the Spoken Tutorial project.
 Please download and watch it.

@@ Line 460: / Line 460: @@
 |-
-|| '''Slide''': 8
+|| '''Slide Number 8'''
 '''About Spoken Tutorial Project '''
@@ Line 468: / Line 468: @@
 |-
-|| '''Slide''': 9
+|| '''Slide Number 9'''
 '''Spoken tutorial workshops '''
@@ Line 476: / Line 476: @@
 |-
-|| '''Slide''': 10
+|| '''Slide Number 10'''
 '''Answers for THIS Spoken Tutorial '''
@@ Line 495: / Line 495: @@
 |-
-|| '''Slide''': 11
+|| '''Slide Number 11'''
 '''Forum '''
@@ Line 505: / Line 505: @@
 |-
-|| '''Slide''': 12
+|| '''Slide Number 12'''
 '''Acknowledgement '''