Problem 1. The resistivity of an intrinsic semiconductor sample at 280 K was measured to be15 Q·cm. At 320 K, it was 0.6 Q cm. Assuming that the mobilities of both electrons and holesdecrease with temperature as µejh~ 1/T 32, find the bandgap of this material.Problem 2. You wish to create a 10-k2 resistor using an n-type (Na= 0) silicon bar of lengthL = 5 mm and cross-sectional area A = 0.05 mm. Assume complete ionization with no = Na andneglect the hole contribution to conductivity. Electron mobility in this material is known todepend on donor concentration according to an empirical formula (see section 6 of the Wikipediaarticle https://en.wikipedia.org/wiki/Electron_mobility)Hmax - Mminµ(Na) = Hmin +1+ (Na/N,)"with the parameters Umin65 cm²/(V-s), µmax1330 cm/(V s), N,= 8.5·1016 cm³, a = 0.72.(a) Determine the conductivity of your material needed to obtain the desired resistance.(b) Find the doping concentration needed to obtain the desired resistance. You will need toemploy some numerical method to solve this problem. The suggested procedure is to usean iterative solution. Namely, express in terms of conductivity and mobility and use theold Na-value to determine a better approximation. Repeat this procedure until the resultstops changing.

1. Resitivity for a semiconductor is given by following equation ρ=A expEg2kBT Where A is constant…

Problem 1. The resistivity of an intrinsic semiconductor sample at 280 K was measured to be 15 Q·cm. At 320 K, it was 0.6 Q cm. Assuming that the mobilities of both electrons and holes decrease with temperature as leh ~ 1/T 312, find the bandgap of this material.

Problem 1. The resistivity of an intrinsic semiconductor sample at 280 K was measured to be 15 Q·cm. At 320 K, it was 0.6 Q cm. Assuming that the mobilities of both electrons and holes decrease with temperature as leh ~ 1/T 312, find the bandgap of this material.

Modern Physics

3rd Edition

ISBN:9781111794378

Author:Raymond A. Serway, Clement J. Moses, Curt A. Moyer

Publisher:Raymond A. Serway, Clement J. Moses, Curt A. Moyer

Chapter12: The Solid State

Section: Chapter Questions

Problem 12P

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