Efficient Self‐Driven Photodetectors Featuring a Mixed‐Dimensional van der Waals Heterojunction Formed from a CdS Nanowire and a MoTe2 Flake

Heterojunctions formed from low‐dimensional materials can result in photovoltaic and photodetection devices displaying exceptional physical properties and excellent performance. Herein, a mixed‐dimensional van der Waals (vdW) heterojunction comprising a 1D n‐type Ga‐doped CdS nanowire and a 2D p‐type MoTe2 flake is demonstrated; the corresponding photovoltaic device exhibits an outstanding conversion efficiency of 15.01% under illumination with white light at 650 µW cm−2. A potential difference of 80 meV measured, using Kelvin probe force microscopy, at the CdS–MoTe2 interface confirms the separation and accumulation of photoexcited carriers upon illumination. Moreover, the photodetection characteristics of the vdW heterojunction device at zero bias reveal a rapid response time (