The Quantum Expression of the Role of Relaxation Time on Optical Absorption in Semi Conductors

In this work theoretical method based on classical mechanics, Maxwell equations and quantum mechanics is utilized to find the mathematical expression for relaxation time, this expression play an important role in the simulation of quantum semiconductor devices .One has studied the relaxation time in the semi classical approximation, the optical potential, perturbation method and generalized Schrödinger Equation for relaxation time. Theoretical relation between the relaxation time and absorption coefficient is obtained. At last one has studied the quantum mechanical absorption coefficient, absorption coefficient for Maxwell’s equations and quantum mechanics, and parameters affecting absorption coefficient.