Performance optimization of self-powered deep ultraviolet photodetector based on PEDOT:PSS/SnO2 organic/inorganic p–n heterojunction by embedding a nitrogen-doped graphene

A self-powered organic–inorganic p–n heterojunction deep ultraviolet (DUV) photodetector (PD) was fabricated based on the polymer poly(3,4-ethylene-dioxythiophene):polystyrene sulfonate (PEDOT:PSS), with an in situ transferred composite film PEDOT:PSS-nitrogen-doped graphene (NGr)-coated SnO2 microwire. At 0 V bias, responsivity spectra of these two PDs both had a broadband response range 200–400 nm. The introduction NGr helped to reduce surface state and improve shortwave response, resulting blue shift peak position from 280 250 Compared PEDOT:PSS/SnO2 PD, light–dark current ratio PEDOT:PSS-NGr/SnO2 PD improved three orders magnitude 24.76 2.51 × 104; detectivity increased by 40 times 1.45 1011 5.85 1012 Jones; speed accelerated less than 1 s (with rise decay 0.35 0.14 s, respectively). performance improvement attributed intermediate layer forming SnO2, which broadened depletion strength built-in electric field, thereby reducing carrier recombination boosting speed. These findings indicate that introducing is effective way modify detector performance.