Realizing photo-switchable molecular junction and improving their performance has been a major research topic in the field of molecular electronics. Here, we implemented photo-responsive molecular junctions by replacing the top electrode of conventional large-area molecular devices with photo-active organic halide perovskite (OHP)/graphene heterojunction. Furthermore, the mechanism of the photocurrent enhancement was demonstrated by showing the formation of the internal field at OHP/graphene interface, and the subsequent field -driven injection of photo-generated charges from OHP to biphenyl-thiol. Based on this understanding, we could adjust the dipole moment of the molecules to improve the switching performance up to 1000% in the pentafluorobenzen-thiol (PFBT) molecular junction. Through the Landauer model, modulation of charge transport properties in the OHP/graphene/molecular structure under the presence of light is studied, and the comparatively higher photocurrent performance of our experiment to that of the conventional OHP/graphene structure was explained.

Authors : Changjun Lee,^† Junwoo Kim,^† Jonghoon Lee, Woocheol Lee, Minwoo Song, Kyung-Yoon Baek, Jiwon Shin, Jongwoo Nam, Jeongjae Lee, Keehoon Kang* and Takhee Lee* (^†equally first authors, *co-corresponding authors)

Published online: 15 April 2022

Link: https://doi.org/10.1002/adom.202200049