Hybrid Silicon‐Polymer Photodetector Engineered Using Oxidative Chemical Vapor Deposition for High‐Performance and Bias‐Switchable Multi‐Functionality

Abstract

AbstractBlack silicon (b‐Si) featured by anti‐reflective surfaces is extensively studied to realize highly sensitive photodetectors. The key to augmenting the light‐detection capability of b‐Si is to facilitate charge extraction while limiting undesired recombination events at surface defects. To this end, oxidative chemical vapor deposition (oCVD) is leveraged to form a highly conformal and conductive (3000 S cm−1) organic transport layer, poly(3,4‐ethylenedioxythiophene) (PEDOT), on b‐Si nanostructures. The oCVD PEDOT instrumentally extracts photo‐induced charges, through which b‐Si photodetectors implementing oCVD PEDOT achieve a superior photo‐detectivity of 1.37 × 1013 Jones. Furthermore, by engineering the pore dimension of b‐Si, a mode‐tunable Si photodetector is contrived, where the functions of broad‐band and visible‐blinded modes are switched facile by a bias polarity. The unprecedented device paves the way for extending the applications of Si detectors toward novel sensory platforms such as night‐vision, motion tracking, and bio‐sensing.