Abstract
Abstract
Surface defects seriously affect the electronic properties of the optoelectronic devices. In this paper, the surface defect analysis of GaAs thin-film solar cells grown by molecular beam epitaxy is carried out by a photon emission microscope. Two types of oval defects at the locations of the luminous spots are observed. The morphology and chemical composition analysis indicates that GaAs dust contamination on the wafer surface and excessive As clusters are the origins of oval defects. The electrical property analysis shows that oval defects in the epitaxial layer should be one of the important reasons for the nonideal leakage current of the GaAs thin-film solar cell.