Photocurrent Enhanced in UV-vis-NIR Photodetector Based on CdSe/CdTe Core/Shell Nanowire Arrays by Piezo-Phototronic Effect

For the wide application of photodetection, the type-II heterojunction structure was applied to the CdSe/CdTe core/shell structure nanowire arrays, and the detection range of the device has been successfully extended to near-infrared light from UV-visible light. The UV/visible/NIR photodetector was fabricated based on vertically aligned CdSe/CdTe core/shell nanowire arrays, which were synthesized by chemical vapor deposition and pulse laser ablation methods. The photodetector performance under UV (385 nm), blue (465 nm), and near-IR (850 nm) illumination was greatly improved by applying a compression load as a result of the piezo-phototronic effect, which is a three-way coupling effect of piezoelectricity, semiconductor, and optical excitation in piezoelectric semiconductors. This work proves that the photodetector integrated on a CdSe/CdTe core/shell nanowire array can effectively improve its performance by the piezo-phototronic effect, and owing to the unique type-II heterojunction structure of CdSe/CdTe core/shell nanowire, the detection range of the device can be extended to near-infrared light.