Ultrasensitive photodetectors, capable of operating without external power sources, are essential for future applications in wireless surveillance, weather forecasting, remote monitoring, and power-constrained environments. This study introduces, for the first time, an island-like design for self-powered and ultrasensitive photodetectors based on 3C-SiC/Si heterojunctions. The proposed architecture enables electron confinement, effectively suppressing lateral diffusion losses and maximising carrier collection at the electrodes, while providing short and unobstructed pathways for efficient charge carrier transport. The fabricated device operates under zero external bias and demonstrates an outstanding performance at 637 nm wavelength, including a photoresponsivity of ∼0.34 A W −1 , detectivity of ∼1.77×10 11 Jones, external quantum efficiency (EQE) of ∼65%, and fast rise and decay times of 390 and 460 µs respectively. These results highlight the significant potential of advanced architectural designs for energy harvesters, micro/nanoelectromechanical systems, and sensing applications. Furthermore, this work lays the foundation for developing next-generation optoelectronic devices by employing electron-confined structures in diverse semiconductor materials to achieve exceptional performance.
Tran et al. (Mon,) studied this question.