Optimization of GaN Nanorod Growth Conditions for Coalescence Overgrowth.

摘要

The growth and fabrication of GaN nanorod (NR) light-emitting diode (LED) arrays have attracted much attention because of their advantages of higher crystal quality, larger sidewall emission area, and non-polar or semi-polar quantum well (QW) formation. This report describes development of regularly-patterned GaN NR LED arrays grown on a patterned template with either continuous or pulsed growth mode using metal-organic vapor-phase epitaxy (MOVPE). Such an array device is expected to be useful for practical lighting application. Usually, with the pulsed growth mode, by switching group-III and V sources on and off alternatively, the NR geometry can be more uniform over an array. InGaN/GaN QWs can be deposited on the c-plane top face, m-plane sidewalls, and {1-101}-plane slant facets on a c-axis-oriented NR with the highest (lowest) growth rate in the c-plane ({1-101}-plane). After the overgrowth of p-GaN on an NR with n-GaN core and QW deposition, an NR LED array can be implemented by covering the NRs with a transparent conductor. It has been demonstrated that the optical and electrical performances of an NR LED array can be comparable to those of a planar LED. Further developments in NR LED growth and process techniques can lead to an outperforming LED device with the NR structure.