Magic of Solvents: Effect of Processing Solvents on Hole Transport in Organic Semiconductor Small Molecules

Abstract

Organic semiconductor small molecules (SMs) attract much attention to the design of various emerging photovoltaic and optoelectronic devices. High charge‐transport characteristics of SMs are important prerequisite for achieving outstanding performance of electronics. Herein, four promising SMs are investigated in terms of modulating charge‐transport properties by solvent engineering. It is shown that the hole mobility of thin films based on push–pull SMs can be effectively enhanced by the replacement of chlorobenzene with environmentally preferable hexane without changing a molecular structure of the compounds. As a result, 2–5 times higher hole mobility is achieved for hexane‐processed films that is attributed to the formation of favorable nanoscale morphology of films. This effortless approach can be applied to other organic semiconductor materials to precisely control the morphology and improve their electrophysical properties.