In: Physics
Part IV (30): Provide numerical answers for questions 1 through 5 below and show all your work. The band structure of an intrinsic (Undoped) semiconductor is given by E(k) = k 2 + B (CB) E(k) = -Ak2 (VB) A = 1 x 10-38 Joule-m2 , B = 1eV = 1.6 x 10-19 Joules 1. What is the effective mass of the electrons and holes in this semiconductor? 2. What is the instantaneous velocity of an electron in the conduction band with k=1 x 109 1/m? 3. If an electric field of 1000V/cm is in the semiconductor, what is the drift velocity of electrons if the average time between collisions with the lattice is = 1 x 10-13 sec? 4. What are the mobile electron and mobile hole concentrations at room temp (300K)? 5. What is the probability that an electron is in the specific state described by the wave vector: k=1 x 109 1/m in the conduction band? (Hint, where is the Fermi Level for an intrinsic semiconductor?)