Abstract
Using infrared absorption spectroscopy of hydrogen passivated β-Ga2O3 the temperature dependence of the dominant O – H vibrational line was measured between 5 and 300 K. With increasing temperature, the vibrational line shifts by Δω = 7.8 cm-1 to lower frequency. This is accompanied by a broadening of the vibrational line from Γ = 0.61 to 8.18 cm-1. The data are discussed in terms of elastic and inelastic phonon scattering and exchange coupling. Moreover, the perturbation of the hydrogen potential is evaluated.
Highlights
Wide band-gap semiconductors such as β-Ga2O3 have been attracting attention for high power devices, deep UV, and solarblind photodetectors and transparent conducting oxides (TCO), recently.1–3 This is mainly attributed to its large band-gap of about 4.5 – 4.9 eV3,4 that favors break-down fields as high as 5 to 9 MV/cm.5 This value is susceptible to be further increased since it depends sensitively on the intrinsic defect concentrations and controlled doping of the host lattice
The main hydrogen related center in β-Ga2O3 has been identified as an O – H complex with a dominant vibrational line at a wave number of 3437 cm-1.12 Based on polarization experiments combined with theory it was suggested that the microscopic structure of the H complex is a relaxed Ga vacancy with two hydrogen atoms, VGa – 2H, along the [102] crystallographic direction
In this paper we present a detailed investigation on the thermal properties of the O – H complex in β-Ga2O3
Summary
Wide band-gap semiconductors such as β-Ga2O3 have been attracting attention for high power devices, deep UV, and solarblind photodetectors and transparent conducting oxides (TCO), recently.1–3 This is mainly attributed to its large band-gap of about 4.5 – 4.9 eV3,4 that favors break-down fields as high as 5 to 9 MV/cm.5 This value is susceptible to be further increased since it depends sensitively on the intrinsic defect concentrations and controlled doping of the host lattice. The hydrogen local vibrational mode (LVM) was measured as a function of temperature. A detailed analysis of the experimental results suggests that the observed temperature dependence of the vibrational-mode data can be described with a simple model where the O – H LVM couples to one low-frequency mode.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
