Self-Powered and Broadband Photodetectors Based on High-performance Mixed Dimensional Sb 2 O 3 /PdTe 2 /Si Heterojunction for Multiplex Environmental Monitoring.

Solar-blind ultraviolet (SBUV) to near-infrared (NIR) broadband photodetectors (BB-PD) have important applications in environmental monitoring and other applications. However, it is challenging to prepare SBUV-IR photosensitive materials via simple steps and to construct SBUV-IR broadband devices for multiplex detection with high sensitivity at different wavelengths. Here, self-powered and broadband photodetectors using a high-performance mixed dimensional Sb 2 O 3 nanorod 1-dimension (1D)/monodisperse microdiamond-like PdTe 2 3-dimension (3D)/Si (3D) heterojunction for multiplex detection of environmental pollutants with high sensitivity at broadband wavelength are developed. The 1D/3D mixed dimensional Sb 2 O 3 /PdTe 2 /Si structure combines the advantages of strong light absorption, high carrier transport efficiency of 1D Sb 2 O 3 nanorods, and expansion of interface barrier caused by 3D microdiamond-like PdTe 2 interlayer to improve the photocurrent density and self-powered ability. The efficient photogenerated charge separation enables anon/off ratio of more than 5 × 10 6 . The device exhibits excellent photoelectric properties from 255 to 980 nm with the responsivity from 4.56 × 10 -2 to 6.55 × 10 -1  AW -1 , the detectivity from 2.36 × 10 12 to 3.39 × 10 13  Jones, and the sensitivity from 3.90 × 10 7 to 1.10 × 10 10  cm 2  W -1 without external bias. Finally, the proposed device is applied for the multiplex monitoring of environmental pollution gases NO 2 with the detection limit of 200 ppb and PM 2.5 particles at mild pollution at broadband wavelength. The proposed BB-PD has great potential for multiplex detection of environmental pollutants and other analytes at broadband wavelength.