Enhanced green emission from Er-doped (AlGa)₂O₃ films grown by pulsed laser deposition

Abstract

Erbium (Er) doped (AlGa) 2 O 3 films were deposited on sapphire substrates using pulsed laser deposition. The transmittance spectra and X-ray photoelectron spectroscopy measurements show that transparent (AlGa) 2 O 3 :Er films with a wider bandgap can be achieved by increasing the Al content in the targets. All films exhibit the strongest pure green emission at 550 nm with the wavelength independent of the alloy compositions. A maximum intensity observed at Al content of 0.34 is several times higher than that in Ga 2 O 3 :Er films, indicating that the intensity of green emission can be enhanced by increasing the host bandgap. Our study also reveals that too high Al content has decreased the photoluminescence intensity, which should be related to the degraded crystallinity proved by X-ray rocking curve. These results suggest that (AlGa) 2 O 3 :Er film is a promising material for fabricating efficient green luminescent devices.

Color-Tunable Light-Emitting Diodes Based on Rare Earth Doped Gallium Oxide Films

“…(e) Al and Er contents in films as a function of Al contents in targets x t . Reproduced with permission from ref . Copyright 2020 The Japan Society of Applied Physics.…”

“…(b) Dependence of the intensity of 4 S 3/2 - 4 I 15/2 transition on the Al contents x in films. Reproduced with permission from ref . Copyright 2020 The Japan Society of Applied Physics.…”

“…Additionally, it has been observed that the temperature quenching effects exhibit an inverse relationship with the bandgap value of the host material. , Gallium oxide (Ga 2 O 3 ), which exhibits a significantly larger bandgap (4.9 eV) compared to GaN, is expected to be an excellent host material. In this spotlight article, we review the progress made toward achieving color-tunable LEDs based on RE doped Ga 2 O 3 semiconductors. − We have systematically studied the structural and optical characteristics of rare earth (Eu, Er, and Tm) doped Ga 2 O 3 films grown by pulsed laser deposition (PLD) and have demonstrated red, green, and blue LEDs based on these Eu, Er, and Tm doped Ga 2 O 3 films and achieved color-tunable LEDs using Eu, Er, and Tm codoped Ga 2 O 3 films.…”