Internal voltages in GaInP∕GaInAs∕Ge multijunction solar cells determined by electroluminescence measurements

Abstract

We analyze electroluminescence spectra of a GaInP∕GaInAs∕Ge triple-junction solar cell at different injection currents. Using the reciprocity theorem between electroluminescent emission and external quantum efficiency of solar cells allows us to derive the current/voltage curves and the diode quality factors of all individual subcells.