Formation of textured sapphire substrates by self-arrangement process and wet etching for InGaAlN LEDs

Abstract

We report a method of profiled sapphire substrate preparation and growth of InGaAlN light-emitting diode (LED) structures over these substrates. Sapphire substrates with textured front surface were prepared by the simple method of nanoscale gold drops formation on sapphire surface followed by etching in hot H3PO4 acid. Comparison of blue LEDs grown on standard (flat) and profiled sapphire substrates in one epitaxial process shows significant increase in output power due to increased light extraction without deterioration of other LED characteristics. © 2008 Elsevier B.V. All rights reserved.