Effect of GaAs substrate misorientation on InxGa1-xAs crystalline quality and photovoltaic performance

Abstract

This paper presents the quality of InxGa1 - xAs (0<x<0.2) layers grown on GaAs substrate with different miscut angle (2 degrees and 15 degrees) by metal organic chemical vapor deposition. The crystalline quality of InxGa1 - xAs layers was found to strongly depend on indium content and substrate misorientation. The In0.16Ga0.84As solar cells with PN structure were grown on a 2 degrees- and 15 degrees-off GaAs substrates. It was found that the photovoltaic performance of In0.16Ga0.84As solar cell grown on 2 degrees-off GaAs substrate was better than that of In0.16Ga0.84As grown on a 15 degrees-off GaAs substrate, because the InxGa1 - xAs films grown on 15 degrees-off GaAs substrate shows a highly strain relaxation in active layer of solar cell, which causes the high dislocation density at the initial active layer/InxGa1 - xAs graded layer interface. (C) 2010 Elsevier B.V. All rights reserved.