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University of Pennsylvania ESE 521 The Physics of Solid State Energy Devices February 11, 2013 Prof. C. R. Kagan Exam #1 ** Remember to label axes, drawings etc. in all of you work and include all units. Calculate any corrections such as to Ei.1. You have a wafer of uniformly doped GaAs with 1017/cm3Zn acceptors at EA=31 meV. [38 points] A. At 300K, calculate (quantitatively) all relevant energies (EC, EV, EF, Ei, and impurity levels) and draw the band diagram labelingall the energy levels and their quantitativeenergies for the GaAs bar. [12 points] B. As a function of temperature between 1 and 1500 K draw (qualitatively) and describe the temperature dependence of this GaAs bar doped with NA=1017/cm3and in a side-by-side comparison to the temperature dependence (between 1 and 1500 K) of an undoped GaAs bar for the following behaviors: [PS Make sure your comparisons are obvious otherwise you will not be given credit] i. carrier concentration [6 points] ii. Fermi energy [4 points] iii. band gap [4 points] iv. recombination processes (be sure to draw and describe) [6 points]