Mixed-Dimensional InSe–Si Heterojunction Nanostructures for Self-Powered Broadband Photodetectors

High-performance self-powered broadband photodetectors composed of mixed-dimensional (2D–3D) InSe–Si van der Waals heterojunctions (vdWHs) are demonstrated for the first time. Because of the suitable band structures, high electron mobility, and good light absorption of the individual 2D InSe and 3D Si, the 2D–3D vdWHs exhibit an excellent rectifying effect, a broad photoresponse region, high responsivity, good stability, and good optical imaging capability. The electrical and photoresponse performance is superior to that of most other 2D InSe-based vdWHs. The good electrical and photoresponse performance of 2D–3D InSe–Si vdWHs demonstrates their broad applicability in high-performance optoelectronic devices.