Photocurrent, Photovoltage, and Rectification in Large‐Area Bilayer Molecular Electronic Junctions

Abstract

AbstractBilayer donor–acceptor molecular junctions are successfully fabricated with active layer thickness <15 nm to study the mechanism of photo‐induced charge transport. The bilayer devices exhibit lifetimes greater than 1 h with laser irradiation, and a strong dependence of the sign and magnitude of the photovoltage and photocurrent on structure and order of the molecular layers. A distinct feature of the bilayer structure is covalent bonding between the donor and acceptor molecular layers, which permits simultaneous absorption and charge separation across a covalent heterojunction. In addition to providing probes of internal energy levels and charge transport in molecular junctions, photo‐induced currents and voltages may potentially be useful in light‐weight, durable, and flexible photodetectors.