Red luminescence in H-doped β−Ga2O3

Abstract

The effects of hydrogen incorporation into -Ga2O3 thin films have been investigated by chemical, electrical and optical characterization techniques. Hydrogen incorporation was achieved by remote plasma doping without any structural alterations of the film; however, Xray photoemission reveals major changes in the oxygen chemical environment. Depth-resolved cathodoluminescence (CL) reveals that the near-surface region of the H-doped Ga2O3 film exhibits a distinct red luminescence (RL) band at 1.9 eV. The emergence of the H-related RL band is accompanied by an enhancement in the electrical conductivity of the film by an order of magnitude. Temperature-resolved CL points to the formation of abundant H-related donors with a binding energy of 28 ± 4 meV. The RL emission is attributed to shallow donor-deep acceptor pair recombination, where the acceptor is a VGa-H complex and the shallow donor is interstitial H. The binding energy of the VGa-H complex, based on our experimental considerations, is consistent with the computational results by Varley et al.

Non‐oxidative Dehydrogenation of Methanol to Formaldehyde over Bulk β‐Ga2O3

“…Thus, the Raman spectra were measured on the low energy side flank of a red fluorescence emission, the intensity of which is increasing with temperature in H 2 . In literature, the presence of red luminescence has been related to oxygen vacancies, [54] but also recently to hydrogen dissolved in Ga 2 O 3 [55] . Bulk processes are indeed involved, because this luminescence can only be removed by annealing in O 2 at 650 °C.…”

“…In literature, the presence of red luminescence has been related to oxygen vacancies, [54] but also recently to hydrogen dissolved in Ga 2 O 3 . [55] Bulk processes are indeed involved, because this luminescence can only be removed by annealing in O 2 at 650 °C. Dong et al [56] performed calculations describing the formation of oxygen vacancies on Ga 2 O 3 as a function of oxygen treatment and concluded that the presence of oxygen increases their formation energy.…”

Current State of Ga2O3-Based Electronic and Optoelectronic Devices. Brief Review

“…Huynh et al in ref. [40] discussed in detail the effect of red luminescence in hydrogen doped gallium oxide. Inclusion of hydrogen in the -Ga 2 O 3 structure decreases layer resistance from 10 10  / sq to 4•10 8  / sq at 300 K. A high-valence gallium oxide with a binding energy 533.4 eV if hydrogen doping is present, H-radicals are absorbed in -Ga 2 O 3 and form strong bonds with oxygen atoms.…”

Progress in atomic layer deposited [alpha]-Ga2O3 materials and solar-blind detectors

“…Luminescence of β-Ga 2 O 3 generally exhibits mainly UV (3.2-3.6 eV), blue (2.8-3.0 eV) and green (2.5 eV) lines, [34][35][36] but a red (1.7-1.9 eV) line has also been reported. [37][38][39] The UV line as been ascribed to recombination between free electrons and self-trapped holes (STHs), while the other lines relate to donor acceptor pair recombination involving a range of intrinsic (e.g. V O , V Ga , Ga i ) or extrinsic (e.g.…”