Temperature dependence of luminescence characteristics from Eu doped Ga₂O₃ thin films excited by synchrotron radiation source

Abstract

Ga2O3 thin film with Eu doping was prepared on p-Si substrate by pulsed laser deposition to investigate the temperature dependence of photoluminescence from Eu3+ and host. The obtained Ga2O3:Eu thin film has a polycrystalline monoclinic structure and smooth surface. The film exhibits multiple sharp emissions originating from Eu3+ dopants, as well as broad defect-related emissions in the UV-green region from Ga2O3 host. With increasing the temperature from 21 K to room temperature, the red emission from Eu3+ keeps unchanged in the wavelength, and remains ~55% PL intensity. Meanwhile, Ga2O3 defect-related ultraviolet and blue emissions experience a strong thermal quenching and a distinct red shift following the Varshni equation and Bose-Einstein expression. These experimental data will provide reliable guide for fabricating efficient luminescent devices based on rare-earth doped Ga2O3.