Interfacial quality is a key determinant of semiconductor optoelectronic performance, governing carrier transport, recombination, and noise, and often limiting ultimate device figures of merit. To address interfacial constraints, we introduce a damage-free, complementary interface optimization by combining an ultrathin ZrO2 passivation formed via room-temperature photochemical deposition with van der Waals (vdW) Au contacts. The conformal ZrO2 interlayer suppresses surface trap states and increases the effective Schottky barrier height to 1.24 eV, whereas vdW metal contacts minimize interfacial damage and mitigate metal-induced gap states. Implemented in GaN ultraviolet photodetectors, this vdW Au/ZrO2/GaN back-to-back Schottky architecture yields ultralow dark current (∼2 × 10-13 A), high responsivity (20.26 A/W with internal gain ∼70), fast temporal response (rise time ∼50 μs), and an ultrawide linear dynamic range of 141.47 dB. Specific detectivity exceeds 1 × 1012 Jones under the 1/f noise limit, corresponding to a noise-equivalent power on the order of 10-14 W. Benchmarking against state-of-the-art GaN Schottky photodiodes and commercial UV detectors shows improvements of one to three orders of magnitude in key performance metrics. This room-temperature, solution-processable, vacuum-free strategy integrates damage-free vdW contacts with photochemical dielectric passivation to reduce interface state density and enhance carrier transport, providing a versatile and scalable platform for high-performance wide-bandgap optoelectronic devices.
Duan et al. (Tue,) studied this question.