High performance of GaN thin films grown on sapphire substrates coated with a silica-submicron-sphere monolayer film

A high-performance, GaN-based light emitting diode (LED) was prepared using a metal organic chemical vapor deposition method on a silica-sphere, monolayer-coated sapphire substrate. Various surface coverage ratios of the silica submicron spheres with diameters ranging from 300 to 550 nm were deposited on the sapphire substrate using a spin-coating method. The LED output power was increased 2.5-fold compared with the LED constructed without silica spheres and uniform light distribution was achieved. In addition, LED output power was dependent on silica-sphere size and surface coverage of the substrates. (C) 2008 American Institute of Physics.