【Device Papers】High-performance solar-blind photodetector of β-Ga₂O₃ grown on sapphire with embedding an ultra-thin AlN buffer layer

      Researchers from the High-performance solar-blind photodetector of β-Ga₂O₃ grown on sapphire with embedding an ultra-thin AlN buffer layer have published a dissertation titled "High-performance solar-blind photodetector of β-Ga₂O₃ grown on sapphire with embedding an ultra-thin AlN buffer layer" in Journal of Alloys and Compounds.

Abstract

      The authors reported the MOCVD growth of high-quality β-Ga₂O₃ on c-plane sapphire substrate, resulting in the achievement of high performance solar blind deep UV photodetectors by introducing an ultra-thin AlN buffer seed layer (BSL). Compared with the direct growth of Ga₂O₃ on the sapphire, the oxygen vacancy of β-Ga₂O₃ is reduced after introducing an AlN BSL and the full width at half maximum (FWHM) of (-201) diffraction peak becomes narrower. The dark current is reduced by 1000 times and from 10⁻¹⁰ A down to 10⁻¹³ A for the metal-semiconductor-metal planner photodetector of β-Ga₂O₃ thin film with the AlN BSL. And the detectivity reaches 4.65×10¹⁵ cm·Hz^1/2·W at 5 V bias. This improvement in performance is derived from the improvement of the growth quality of β-Ga₂O₃ mediated by the AlN BSL due to the decrease of lattice mismatch. The defects in β-Ga₂O₃ are reduced, the carrier concentration is reduced, the Fermi level is shifted, the depletion region is widened, the probability of electron tunneling in the dark state is reduced, and the dark current is effectively reduced.

DOI：

doi.org/10.1016/j.jallcom.2024.176156