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Solid State Device Theory Exercise

Solid State Device Theory Exercise. See attached file for full problem description.

1. A semiconductor sample has the band diagram below.

(a) Is this semiconductor in equilibrium? Explain.
(b) Sketch the electric field versus x.
(c) Roughly sketch n and p versus x.
(d) Make a rough sketch of the electron drift current density and the electron diffusion current
density versus x. Be sure to graph the proper polarity of the current densities at all points.

2. A semi-infinite p-type bar is illuminated with light generating GL electron-hole pairs/cm3
-s
uniformly throughout the volume of the semiconductor. Simultaneously, carriers are e

3. A p-Si photoconductor is to detect optical pulses having the waveform shown below.

Each pulse generates electron-hole pairs (ehp). When the pulse terminates, the ehp recombine
according to the relation where t = 0 refers to the time when the light pulse is turned off. ∆np(t) must have decreased to 0.01∆np(0) before the next pulse is applied for proper photoconductor operation.
For σn = 10-16 cm2
and vth = 107
cm/s, determine NT for this to happen.

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Solid State Device Theory Exercise. See attached file for full problem description.

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