Ge doped GaN with controllable high carrier concentration for plasmonic applications

Abstract

Controllable Ge doping in GaN is demonstrated for carrier concentrations of up to 2.4 × 1020 cm-3. Low temperature luminescence spectra from the highly doped samples reveal band gap renormalization and band filling (Burstein-Moss shift) in addition to a sharp transition. Infrared ellipsometry spectra demonstrate the existence of electron plasma with an energy around 3500 cm-1 and a surface plasma with an energy around 2000 cm-1. These findings open possibilities for the application of highly doped GaN for plasmonic devices. © 2013 AIP Publishing LLC.