Radial GaN Nanowire‐Based LEDs

Summary

GaN NW‐based light emitting devices have two different configurations, that is, axial and coaxial (or radial) structures. This chapter discusses the epitaxy and fabrication of radial GaN NW‐based LED by metal‐organic vapor phase epitaxy (MOVPE), and also discusses the progress in the past decade on radial GaN NW‐based LED and the remaining problems. The methods of NW growth mostly found in literature are self‐organized (or self‐assembled) growth and SAG. The self‐organized growth with catalyst is often called “vapor‐liquid‐solid (VLS)” growth mode. In conventional 2D LED devices, in order to enhance the light extraction, surface roughening with nano/micro‐size surface structure is often used to circumvent the low‐light extraction problem caused by the high refractive index of GaN layer. Due to the 3D configuration, GaN NW ensemble‐based devices naturally offer similar or even better function for higher light extraction.