Hybrid Heterostructures of Nanostructured Si Membrane and MoS ₂ for Self‐Powered Photodetectors

ABSTRACT Two‐dimensional transition‐metal dichalcogenides, especially molybdenum disulfide (MoS 2 ), have emerged as a promising channel material for next‐generation electronic and optoelectronic devices due to their atomic thickness and excellent electrostatic integrity. However, the performance of MoS 2 devices on conventional planar silicon (Si) substrates often suffer from limited performance caused by carrier scattering, insufficient electrostatic control, and self‐heating. In this work, we demonstrate a vertical heterostructure of MoS 2 with a Si nanomesh substrate via a scalable process. The Si nanomesh is fabricated through nanosphere lithography and the MoS 2 /Si heterostructure is fabricated by conformal deposition of MoS 2 using reactive magnetron sputtering and atmospheric‐pressure sulfurization. Photodetector based on the nanostructured MoS 2 /Si heterojunction exhibit enhanced electrical conductivity and higher photocurrent compared to planar MoS 2 /Si devices and can be operated without external power. Photocurrent mappings further reveal that the MoS 2 /Si heterojunction region primarily governs the photoresponse, functioning in a photovoltaic mode at zero bias and shifting to an avalanche‐assisted regime under reverse bias. A peak responsivity of 205 mA W −1 is achieved with rise and decay times of 150 and 100 ms, respectively. These results demonstrate that the integration of MoS 2 /Si nanomesh platform offers a CMOS‐compatible and scalable pathway for high‐performance 2D semiconductor electronics and optoelectronics.