Multiple Defect Levels and Isothermal Trapping: Semiconductor Material Quality Evaluation

A solution to the single level Shockley-Read-Hall rate equations developed recently is applied to two multiple level systems. The two systems considered are the multiple discrete level system and the ground excited state or coupled level system. It is shown that the solution to the differential rate equations for the two multiple level systems derived without an approximation lead to a consistent interpretation of the minority carrier time constant. Hence a measure of semiconductor quality may be determined by an assessment of the variation of minority carrier time constant with excess carriers due to an impulse or after steady state conditions.