Defect suppression and optoelectronic property investigation of a self-powered β-Ga2O3/p-Si photodetector grown by pulsed laser deposition

The pulsed laser deposition method is recognized for its ability to minimize defects in semiconductors by carefully controlling gas pressure and temperature during deposition. This study discusses the presence of defect states in β-Ga2O3/p-Si heterojunction created using pulsed laser deposition at different oxygen pressures through deep-level transient spectroscopy (DLTS). When the oxygen pressure rises from 0 to 25 mTorr, the electron trap at EC −1.21 eV associated with an oxygen vacancy vanished, resulting in a 1.6 fold decrease in the total defect density. A gallium vacancy hole trap located at EV + 0.57 eV was identified when the oxygen pressure reached 55 mTorr. The presence of this hole trap suggested that β-Ga2O3 was grown in an oxygen-rich environment. The photoluminescence findings are outstanding and in agreement with DLTS data. The β-Ga2O3/p-Si device showed its peak photoresponsivity at 25 mTorr (330 mA W−1). This shows that carrier transport is improved because defects are reduced. Our discovery provides a possible path for enhancing the high optoelectronic properties of β-Ga2O3/p-Si devices. © 2025 IOP Publishing Ltd. All rights, including for text and data mining, AI training, and similar technologies, are reserved.