The Heteroepitaxy and Characterization of Inp and GaInP on Silicon for Solar Cell Applications

Abstract

ABSTRACTInP and GaInP layers were heteroepitaxially grown on (100) Si substrates by atmospheric pressure MOCVD. TEM and photoluminescence (PL) were used to measure the defect density and the minority carrier lifetime in these structures. The direct growth of InP on Si resulted in either polycrystalline or heavily faulted single-crystal layers. The use of GaAs buffer layers in InP/Si structures gave rise to significantly improved morphology and reduced the threading dislocation density. The best InP/Si layers in this study were obtained by using GaAs-GaInAs graded buffers. Additionally, the growth of high quality GaInP on Si was demonstrated. The minority carrier lifetime of 7 ns in these layers is the highest of any III-V/Si semiconductor measured in our laboratory.