Ultrawide Band Gap Oxide Nanodots (Eg > 4.8 eV) for a High-Performance Deep Ultraviolet Photovoltaic Detector.

Recently, deep ultraviolet (DUV) detectors based on gallium oxide (Ga2O3) have become promising in industrial and aerospace applications because of their inherently ultrawide band gaps (4.5-4.9 eV). Because most of them are difficult to be prepared, the lattice mismatch with the substrate and the expensive cost have to be taken into consideration. Because of such problems, the solution-processible nanodots (NDs) with ultrasmall size provide a solution. Here, we propose to use γ-Ga2O3 NDs as the DUV-sensitive layer to construct a DUV p-i-n-type detector with photovoltaic properties (p-graphene/γ-Ga2O3 NDs/n-SiC). The device exhibits a high photoresponsivity (5.8 mA/W) and detectivity (7.6 × 1010 jones) with a 250 nm source illumination under 0 V bias. Moreover, the DUV/UV injection ratio (R250/R360) reaches 103. These results demonstrate a new way to manufacture low-cost, high-performance DUV detectors based on γ-Ga2O3.