Problem I (30 points): Consider an n-type semiconductor at…
Problem I (30 points): Consider an n-type semiconductor at temperature T. In thermal equilibrium, the electron and hole concentrations are n₀ and p₀, respectively. Assume the nondegenerate limit so that Boltzmann statistics apply.When the semiconductor is uniformly illuminated, it reaches a steady nonequilibrium state with electron and hole quasi-Fermi levels EFn and EFp, and carrier concentrations n and p. Assume that Eg, Nc, and Nv are known.1. Derive an expression for the product np in terms of the quasi-Fermi levels.2. Draw a schematic band diagram showing the positions of the two quasi-Fermi levels under light illumination. 3, When the light is turned off and the semiconductor returns to equilibrium, derive the product of the electron and hole concentrations in terms of Eg, Nc, and Nv.