Answer Happy

The following graph plots the intrinsic carrier concentration for Si, Ge, and GaAs as a function of temperature. The energy bandgap Eg at 300 K and electron and hole effective masses, m, and mp, of Si, Ge, and GaAs are given in the following table. 1016 A T₁ Si Ge GaAs Eg (ev) 1.12 0.67 1.42 ma/me 0.26 0.12 0.068 0.39 mp/mo 0.30 0.50 *mo is the real mass of free electrons. (a) Determine the materials for line A, B, and C. Briefly explain your answer. (b) Comparing the temperatures T, and T2, which one is higher? Please explain. (c) Determine the maximum wavelength of an incident photon that can interact with an electron in the valance band of GaAs and excite it to the conduction band. Please be noted that for photons, the wavelength 2 is related to frequency v by 2-c/v, where e is the speed of light (c=3×10% m/s). (d) What is the probability that a state at the bottom of conduction band in an intrinsic Si sample is occupied by an electron at 7= 300 K? Assuming that the intrinsic Fermi level locates at the mid of the bandgap. n; (cm³) 1014 10¹2 1010 10⁰ 106 B T₂