SIMPLIFIED EVALUATION METHOD FOR LIGHT-BIASED EFFECTIVE LIFETIME MEASUREMENTS

In this letter, we present a simplified evaluation method for light-bi ased photoconductance decay measurements. The measured effective lifet ime is shown to be a differential quantity tau(eff,d), which may diffe r significantly from the actual effective lifetime tau(eff). However, the actual effective lifetime can be approximated by integrating tau(e ff,d) directly over the incident power density of the bias light. The quality of the approximation depends mainly on the surface recombinati on velocity and the wavelength of the used bias light. However, the in accuracy remains well below 10% for most practical cases. (C) 1997 Ame rican Institute of Physics.