Self-Powered and Broadband Photodetectors Based on High-performance Mixed Dimensional Sb₂O₃/PdTe₂/Si Heterojunction...

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 Sb₂O₃ nanorod 1-dimension (1D)/monodisperse microdiamond-like PdTe₂ 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 Sb₂O₃/PdTe₂/Si structure combines the advantages of strong light absorption, high carrier transport efficiency of 1D Sb₂O₃ nanorods, and expansion of interface barrier caused by 3D microdiamond-like PdTe₂ interlayer to improve the photocurrent density and self-powered ability. The efficient photogenerated charge separation enables anon/off ratio of more than 5 × 10⁶. 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 × 10¹² to 3.39 × 10¹³ Jones, and the sensitivity from 3.90 × 10⁷ to 1.10 × 10¹⁰ cm² W^-1 without external bias. Finally, the proposed device is applied for the multiplex monitoring of environmental pollution gases NO₂ 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.