Microwave reflections for carrier lifetime measurements: a comprehensive study on sensitivity and transient response

Abstract

The time-resolved microwave reflection technique is widely used for process control in the photovoltaic community. We demonstrate how to optimize the sensitivity and the reliability of carrier lifetime measurements with this method. Our approach is based on a dielectric multilayer model that allows us to calculate microwave reflection transients from excess carrier decay after pulsed laser excitation. We find that the reflected microwave power mirrors the carrier decay only if the reflector is positioned appropriately.