Growth of high quality GaN nanowalls on Si (111) surface

Abstract

In this article, we propose the formation of GaN nanowall morphology on Si (111) surface by varying nitrogen flux from 2, 4.5 and 6sccm in PA-MBE growth. The optical, structural and electrical properties of these films are investigated. Cathodo-luminescence data suggests that the nanowall network grown at 6sccm show high optical emission and high crystalline quality. The current-voltage (I-V) characteristics of the GaN films exhibit varying rectifying behavior at 1V with forward to reverse current ratios of 39, 155, 388 for the GaN layers grown at 2, 4.5 and 6 sccm while the reverse leakage current values are 1.2×10-3, 2.6×10-4 and 9×10-6 A respectively for these junctions. The good optical and electrical properties observed suggest that GaN/Si heterojunction grown at 6sccm nitrogen flow comprise of low defect density.