Assignment-I
Subject: Electronic Devices
Code: 18EC33
Module 1 & 2
1.
2.
3.
4.
5.
Briefly discuss Bonding forces in solids.
Explain Energy bands with example
Explain Direct and Indirect semiconductors with the neat diagram.
Discuss Hall Effect in semiconductor.
Calculate the approximate donor bonding energy for GaAs(εr=13.2, m*n=0.067mo)
6.
Calculate the conductivity effective mass of electrons in Si. where ml=0.98mo; mt=0.19mo
7.
Explain Qualitative description of Current flow at a pn junction
Explain the following Reverse bias breakdown
1 Zener breakdown
2 Avalanche breakdown
3 Rectifiers
9. Briefly discuss Solar Cells and Photo detectors
10. Explain Light Emitting Diode: Light emitting materials
8.
11. An abrupt Si p-n junction (A = 10-4 cm2) has the following properties at 300 K:
p side
n side
17
-3
Na = 10 cm
Nd = 1015
τn=0.1 µs
τp=10 µs
µp = 200 cm2/V-s
µn = 1300
µn = 700
µp = 450
The junction is forward biased by 0.5 V. What is the forward current? What is the current at a
reverse bias of -0.5 V?
12. A Si solar cell has a short-circuit current of 100 mA and an open-circuit voltage of 0.8 V under
full solar illumination. The fill factor is 0.7. What is the maximum power delivered to a load by
this cell?