A Facile Method for Improving Detectivity of Graphene/p‐Type Silicon Heterojunction Photodetector
Tae Jin Yoo, Soyoung Kim, Min Gyu Kwon, Cihyun Kim, Kyoung Eun Chang, Hyeon Jun Hwang, Byoung Hun Lee
Abstract
Abstract Simultaneous optimization of detectivity and dark current is successfully achieved by modulating the Schottky barrier height of a graphene/p‐type silicon photodetector from 0.42 to 0.68 eV by doping graphene with polyethyleneimine (PEI). At a barrier height modulation of 0.26 eV, the dark current is reduced by three orders of magnitude from 980 nA to 219 pA, and the detectivity is improved by 529% at 850 nm when compared to undoped graphene/p‐type silicon photodetectors. Such a significant performance enhancement confirms that the chemical doping of graphene before device fabrication is a simple yet highly efficient approach to improve the detectivity of heterojunction photodetectors.