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

      Researchers from the Le Quy Don Technical University have published a dissertation titled "Defect suppression and optoelectronic properties investigation of self-power β-Ga₂O₃/p-Si photodetector grown by pulsed laser deposition" in Journal of Physics D: Applied Physics.

Abstract

      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.

DOI：

https://doi.org/10.1088/1361-6463/adab00