Interfacial Reaction Competition in NiO/SiC for High-Performance UV Photodetection

Oxide/wide-bandgap semiconductor heterojunctions suffer from severe interfacial defects arising from lattice and chemical mismatch, limiting device performance. Here we report a self-organized oxygen-gating (SOOG) strategy, where competing interfacial oxidation and Ni-Si interdiffusion spontaneously form an ultrathin SiO_x/Ni-Si bilayer interphase at the NiO/4H-SiC interface. The SOOG-engineered buried interphase results in an over 85% reduction in dark current, 1800% enhancement in responsivity, and ultrafast response times of 3/5 ms, nearly 2 orders of magnitude faster than untreated devices. Our findings indicate that the SOOG strategy provides an effective route for buried interphase engineering by harnessing reaction competition. This approach effectively addresses the critical issue of interfacial defects in oxide/wide-bandgap semiconductor heterojunctions, enabling next-generation photodetectors with high response speed and sensitivity. In turn, it is also applicable to broader applications in high-performance electronic and photonic devices.