Photo-switchable field-effect transistors based on two-dimensional stilbene oligomer crystals

Abstract

We demonstrate the utilization of photochromic two-dimensional (2D) organic single crystals as the channel of organic field-effect transistors (OFETs). High-quality millimeter-sized 2D crystals of semiconducting 1,4-bis(4-methylstyryl)benzene (p-MSB) are grown via a simple one-step interfacial self-assembly method. A typical photo-switching behavior is observed, and the drain current can be reversibly modulated by the alternation of low-intensity irradiation (395 nm) and dark storage, confirming the occurrence of trans–cis photoisomerization of stilbene in the 2D-crystalline phase. As a comparison, different photoresponsive behaviors are observed in OFETs based on bulk p-MSB crystals, indicating that highly efficient photoisomerization and photo-switching behavior occur when the crystal thickness of the conduction channel decreases down to a few molecular layers.