Effect of curved graphene oxide in a GaN light-emitting-diode for improving heat dissipation with a patterned sapphire substrate

Abstract

This article reports on the development of a reduced graphene oxide (rGO)-embedded light-emitting diode (LED) on a patterned sapphire substrate (PSS), for improving heat dissipation and reducing threading dislocations. The prototype device fabrication involves the generation of scalable curved graphene oxide microscale patterns on a PSS, followed by thermal reduction and epitaxial lateral overgrowth of GaN in a metal-organic chemical vapor deposition system with a one-step process. Using the forward voltage method, the junction temperature T-j of the rGO-embedded LED was found to be reduced by about 17 degrees C from the similar to 62 degrees C of the LED grown without the rGO buffer layer. Temperature-dependent light output power and chip surface temperature measurements were also performed and the results are discussed.