Interaction between hydrogen and gallium vacancies in β-Ga2O3

Abstract

In this paper, the revised Heyd-Scuseria-Ernzerhof screened hybrid functional (HSE06) is used to investigate the interaction between hydrogen with different concentrations and gallium vacancies in β-Ga2O3. The hydrogen can compensate a gallium vacancy by forming hydrogen-vacancy complex. A gallium vacancy can bind up to four hydrogen atoms, and formation energies decrease as the number of hydrogen atoms increases. Hydrogen prefers to bind with three coordinated oxygen. The bonding energy and annealing temperatures of complexes containing more than two hydrogen atoms are computed, and show relatively high stability. In addition, vacancy concentrations increase with the increasing vapor pressures. This paper can effectively explain the hydrogen impact in β-Ga2O3.

Impact of deep level defects induced by high energy neutron radiation in β-Ga2O3

“…[35][36][37][38][39] Hydrogen-gallium vacancy complexes (i.e., V Ga -H, V Ga -2H) might also play a role since irradiation can affect the degree of H saturation of V Ga with different charge state transitions, (0/−1), (−1/−2), (−2/−3), etc., which has also been reported for proton-implanted β-Ga 2 O 3 with the V Ga -2H complex formation, 44 and possibly cause Frenkel pair generation. 39,45 Regarding the E C −4.48 eV state that remained unaffected after irradiation for both doses, this energy level is close to those that have been predicted for vacancies; 38,46 however, Note that the concentrations of the DLOS traps before and after irradiation are likely even greater (but at same ratio) than shown here due to their small optical cross sections causing an underestimation of these values.…”

Hydrogen-doped viscoplastic liquid metal microparticles for stretchable printed metal lines

“…6) and the H  formation was accelerated by DCP. Conductivity of Ga-or In-based alloys is dependent on the extent of Hdoping 28,35,36 . Since H  generation is proportional to the fraction of ethylene (E) in PEVA, the conductivity increased as E (red line in Fig.…”

Trapping of multiple H atoms at the Ga(1) vacancy in β -Ga2O3

“…They support these conclusions by using density functional theory (DFT) to calculate the binding energies of one, two, three, and four H atoms at the Ga(1) vacancy. These processes, if supported by subsequent results, could play significant roles in the understanding 2 and applications 3,4 of b-Ga 2 O 3 , as noted by Polyakov et al 5 However, the models of these defects and of the Ga(1) vacancy suggested by Islam et al 1 and earlier by Wei et al 6 involve an unshifted configuration of this defect and have not taken account of the remarkable spontaneous restructuring of the Ga(1) defect that has been found to take place, both with and without trapped H. Specifically, the Ga(1) vacancy is metastable against lower-energy shifts into two inequivalent configurations (Fig. 1) in which a neighboring Ga(1) moves to an interstitial position halfway between its original site and the site of the vacancy.…”

“…However, we find that each of these three-and four-H unshifted-vacancy configurations would have at least one vibrational mode with a strong [010] component, and there is no experimental evidence [15][16][17] for such modes. Thus, the absence of any defects with H atoms trapped at an unshifted Ga(1) vacancy with the structures proposed by Islam et al 1 or Wei et al 6 in spite of their low energy appears to be a puzzle.…”

“…The absence of experimental evidence for multiple hydrogens trapped at an unshifted Ga(1) vacancy means that physical conclusions 1,6 based on trapped hydrogens must be obtained from the actual, shifted, structures of these defects. While defects with three or four hydrogen atoms trapped at an unshifted Ga(1) vacancy may have lower energy than for defects with a shifted Ga(1) vacancy, the absence of pathways to reach these configurations by the sequential trapping of additional H atoms at temperatures for which these defects have been investigated can explain their absence in recent experiments.…”