Defect suppression and optoelectronic properties investigation of self-power β-Ga2O3/p-Si photodetector grown by pulsed laser deposition

Abstract The pulse laser deposition method is recognized for its ability to minimize defects in semiconductors by carefully controlling gas pressure and temperature during deposition. This research 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 rose 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 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 were outstanding and in agreement with DLTS data. The β -Ga2O3/p-Si device showed its peak photoresponsivity at 25 mTorr (330 mA/W). This shows that carrier transport was improved because defects were reduced. Our discovery provides a possible path for enhancing the high optoelectrical properties of β-Ga2O3/p-Si devices.