【Device Papers】Anisotropic optical properties and polarization-sensitive solar-blind photodetector of polycrystalline Ga₂O₃

      Researchers from the Inner Mongolia University have published a dissertation titled " Anisotropic optical properties and polarization-sensitive solar-blind photodetector of polycrystalline Ga₂O₃" in Physica Scripta.

Abstract

      Gallium oxide (Ga₂O₃), as one of typical ultrawide bandgap semiconductors, has been extensively employed to fabricate authentic solar-blind ultraviolet photodetectors, owing to its bandgap of around 4.9 eV and absorbance cut-off wavelength of 280 nm. It exhibits advantage of materials in nature, compared to some other multi-element alloyed semiconductors. Currently, most reports on Ga₂O₃-based photodetectors are focused on sensing light wavelength and intensity. However, light carriers additional third semantide, i.e., polarization state. In this work, a solar-blind deep ultraviolet photodetector based on plasma-enhanced chemical vapor deposition (PECVD)-grown polyscrstalline Ga₂O₃ thin film is fabricated and analysed, for sensing the wavelength, intensity and polarization state of incident ultraviolet light. The dark current is as low as 7.1 × 10⁻¹³ A, responsivity is 189 mA W⁻¹, specific detectivity is ∼10¹³ Jones and external quantum efficiency is 30%. This photodetector could display good performance for sensing the light wavelength and light intensity. Moreover, the angle-resolved polarization Raman spectroscopy (ARPRS) is used to analyse the anisotropic optical properties of prepared Ga₂O₃ thin film. And, the polarization state photodetection is measured and discussed in detail, the polarization dichroic ratio is ∼1.3, indicating an ability to perform anisotropic optical photodetection.

DOI：https://doi.org/10.1088/1402-4896/adf15b