Effect of dislocations on the efficiency of thin-film GaAs solar cells on Si substrates

Abstract

Recombination loss at dislocations is the predominant loss mechanism in thin-film GaAs solar cells on Si substrates. Cell parameters are calculated based on a simple model in which dislocations act as recombination centers. Excellent agreement is observed between theory and experiment. It is indicated that one could fabricate thin-film GaAs solar cells with an efficiency of 17–18% on Si substrates if the dislocation density is less than 5×105 cm−2.