Theory Research on the Solar Cell Martial of GaN by a Novel Method

Abstract

Abstract-Solar cell material GaN films were grown on 6H-SiC by metalorganic chemical vapor deposition (MOCVD).An in situ SiNx interlayer was employed during the growth process, which acted as a nano-mask to promote epitaxial lateral overgrowth. The threading dislocations (TDs) density in the films may be reduced to 1.7×108 cm−2 by the SiNx interlayer. The TD reduction method relies on the formation of facetted islands on the SiNx-treated GaN surface. Some TDs bend to the facets of GaN islands, some TDs with an opposite Burgers vector could be annihilated when bending over by 90° and forming half-loops after reacting with each other at the interface. The improvement of surface morphology, optical quality and train relaxation were achieved by the SiNx interlayer also.The GaN films reported here will provide various opportunities for the development of high efficiency and high performance semiconductor devices based on GaN material. Subsequent research has laid a theoretical foundation.