Interference effects on room-temperature photoluminescence spectra of GaAs/Ge space solar cells

This paper describes a new method, based on room-temperature photoluminescence (PL), for time-saving and nondestructive characterization of thin emitter GaAs/Ge solar cells used for space power applications. It has been shown that the interference phenomena produced between the PL directly escaping from the surface and the PL reflected from the GaAs/Ge interface can provide information on the doping level, thickness and uniformity of the GaAs structure deposited on Ge substrates. This method can be utilized for the quality control of mass-production of GaAs/Ge solar cells for space power applications.