Utilizing the Ability of Few-Layer MoS₂ Integrated with MOCVD-Grown ZnGa₂O₄ for Thermally Stable Deep Ultraviolet Detection Performance

A thermally robust deep ultraviolet photodetector (DUV PD) was developed by utilizing the complementary characteristics of few-layer (FL)-MoS 2 as a van der Waals heterostructure on top of the MOCVD-grown zinc gallate. Using a low-cost technique, a type I straddling heterointerface is formed by selectively scratching the FL-MoS 2 with a razor blade on the zinc gallate substrate. Not only does this creative method provide outstanding stability across a broad temperature range, but it also provides exceptional sensitivity to DUV light between 200 and 280 nm. The detectivity of the device is 4.9 × 10 18 Jones under a 10 V bias, and a fast response of 77 ms is realized. The device can significantly detect extremely low levels of noise, having a noise equivalent power (NEP) of 1.2 × 10 –20 A/Hz 1/2 . The band alignment in FL-MoS 2 /ZnGa 2 O 4 unveils a valence band offset of 1.75 eV and a compelling conduction band offset of 1.65 eV. The performance of the photodetector in DUV is far better than that of Si APD available in the market (APD130A2(/M) from Thorlabs Inc.), with a detectivity of ∼10 13 Jones, a responsivity ∼2 A/W, and NEP 2.1 × 10 –13 A/Hz 1/2 . The excellent performance of this FL-MoS 2 /ZnGa 2 O 4 /FL-MoS 2 makes it highly compatible with practical applications of DUV photodetectors under elevated-temperature environments.