This document summarizes the results of three assignments on modeling semiconductor junctions in Python. For each assignment, the student plotted the electric potential, electric field, charge concentration, electron/hole concentration, and energy band diagrams. In the first assignment on an abrupt PN junction, the electric field was negative due to opposite charges in the depletion regions. In the second assignment on a linearly graded junction, the electric field was positive as both regions contained positive ions. The third assignment varied the length of the P-channel and found the recombination rate and voltage changed accordingly.

1. Assignment -3
Roll No – 193070082
Name-K. Vishnu Vamsi Yadav
1.Abrupt Junction :
In this question i assumed V initial= -0.3495 and V final=0.3495.and I plotted
the results in the below plots.
A).Electric Potential:
B) Electric Field:

2. C) Charge concentration (ρ/q)
D).Electron (n) and Hole (p) concentrations:
E).Energy Band Diagrams

3. B) Linearly graded Junction:
A) Electric Potential:
B).Electric Field
C) Charge Concentration:

4. D) Electron and Hole Concentration:
E) Energy Band Gap:

5. 2)
In this question I assumed voltage from 0.4 volts to 0.3495 volts.
A) Electric Potential
B) Electric Field
C) Charge Concentration:

6. D) Electron and Hole Concentration:
E) Energy Band Diagram
In this problem we have taken the n-n+ doped semiconductor .but in question 1 we have
taken p-n junction diode we already know that in depletion region of p-n junction diode p
side depletion have negative ions and n side depletion junction have positive ions. according
to the poisons equation if we integrate these charges we will get the negative electric field
electric field. the same electric field is plotted.in question 1.
But in the question 2 we have taken the n-n+ junction diode.so both of the junctions have the
positive ions in depletion region . according to poisons equation if we integrate the depletion
side positive ions i got positive electric field.

7. 3)
A) Electric Potential:
B) Electric Field:

8. C) Charge Concentration:
D) Electron(n) and Hole(p) Concentration:

9. E).Energy Band Diagram:
As length of the p channel is changing that is decreasing the value of the recombination rate
in base also decreases.so the voltage level also changing according to the length of the base.