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Professor Saif Islam’s Group Makes the Cover of PSSA

Spontaneous delamination via compressive buckling facilitates large-scale β-Ga2O3 thin film transfer from reusable GaAs substrates

Authors:  Ahmet Kaya, Daniel M. Dryden, Jerry M. Woodall, M. Saif Islam

Abstract

The fabrication and transfer via spontaneous delamination of large-area, high-quality β-Ga2O3nanoscale thin films with centimeter-scale dimensions is demonstrated via thermal oxidation of reusable GaAs substrates. The films are characterized by using X-ray diffraction, energy dispersive spectroscopy, Raman spectroscopy, and scanning electron microscopy. The film demonstrates good mechanical flexibility facilitating reliable transfer. The β-Ga2O3 film’s optical band gap and Schottky barrier height with gold are 4.8 and 1.03 eV, respectively. Electrical and optical properties of the transferable β-Ga2O3 thin films exhibit a potential for application in solar-blind photodetectors. The scale of the β-Ga2O3 films transferred herein exceeds what the research community has reported to-date by more than four orders of magnitude. The macroscopic dimensions of the transferred films may offer a remedy for the low thermal conductance of β-Ga2O3 via transfer onto substrates with high thermal conductivity.