Hybrid PEDOT:PSS/SiC heterojunction UV photodetector with superior self-powered responsivity over A/W level

Abstract

In this Letter, an ultraviolet photodetector constructed on a simple vertical PEDOT:PSS/SiC hybrid heterojunction with superior self-powered performance was reported. Benefitting from the abundant charge carrier concentration in 4H-SiC substrate and the large built-in field at PEDOT:PSS/SiC heterointerface, the SiC based photodetector (PD) realized self-powered responsivity over A/W level, even comparable with many reported 4H-SiC avalanche photodiodes. Upon illumination with deep-UV wavelength at 254 nm, the responsivity, detectivity, and external quantum efficiency of the fabricated PD reached up to 2.15 A/W, 1.9 × 1013 Jones, and 1053%, respectively. Furthermore, the rise/decay time was as fast as 58.6/41.5 ms, the on–off switching ratio was as large as 8.73 × 103, the spectral rejection ratio (R254/R390) was as high as 4.3 × 103, and the lifetime reliability was over 195 days. Serving as a sensing pixel, the designed heterojunction PD demonstrated excellent imaging capability in homemade UV imaging system, showing promising applications in future energy-conservation photoelectronic system.