Lowered stimulated emission threshold of zinc oxide by hydrogen doping with pulsed argon–hydrogen plasma

Abstract

The effects of hydrogen doping on the optical and electrical properties of zinc oxide (ZnO) films were investigated. We prepared about 50-nm thick ZnO films on a sapphire substrate by using a pulsed laser deposition method and used a pulse-modulated inductively coupled plasma technique (PM-ICP) to intentionally insert hydrogen into the films. An increase in the electron concentration by hydrogen doping indicated that hydrogen is actually a cause of shallow donors. Moreover, the excitation intensity threshold for optically pumped stimulated emissions was significantly reduced after hydrogen doping.