Giant superlinear and high-temperature stable ultraviolet photodetectors based on a single SiC/amorphous BN nanowire

High illumination power and high temperature can severely impact the photoresponse performance and operational stability of SiC nanowire-based UV photodetectors (PDs) due to the increased carrier recombination, saturation absorption, and thermal degradation. To overcome these limitations, a novel single-nanowire UV photodetector based on a SiC/amorphous BN (a-BN) core–shell heterostructure is successfully constructed, which efficiently improves surface passivation, thermal stability, and separation of photoexcited carriers. Under intense 365 nm illumination, the device exhibits a remarkable superlinear photoresponse of 2.39, far exceeding the typical sublinear behavior of SiC PDs, accompanied by high responsivity (2541.87 A W−1), detectivity (2.08 × 1010 Jones), external quantum efficiency (EQE) (8.65 × 105%), and rapid rise/decay times (76/83 ms). Even at 200 °C, it maintains robust performance with a responsivity of 226 A W−1, detectivity of 1.48 × 109 Jones, and EQE of 0.77 × 105%, demonstrating the excellent thermal endurance. Theoretical analysis attributes this robust superlinear response to enhanced carrier separation and transport, rapid saturation of interfacial states, accelerated detrapping, and suppressed recombination within the SiC/a-BN and Au–SiC/a-BN heterojunctions. This study provides a solid foundation for the development of thermally stable superlinear UV PDs with potential for high-resolution imaging in harsh environments.