Gallium nitride (GaN) on sapphire substrates for visible LEDs
This chapter describes GaN epitaxial materials grown on sapphire substrates since they are a very important technological platform for visible light-emitting diodes (LEDs) and solid-state lighting technology. The chapter begins with the historical background of GaN material development and describes the fundamental properties of sapphire as a substrate for the epitaxial growth of GaN. The chapter then discusses fundamental, technical and economic aspects of GaN on sapphire, relevant for LEDs, including strained heteroepitaxial growth, epitaxial overgrowth and non-polar and semi-polar GaN growth, followed by a brief outlook of LEDs based on GaN on sapphire.
