Fabrication and physical properties of self-assembled ultralong polymer/small molecule hybrid microstructures

One-dimensional (1D) organic semiconductor micro/nano-structures (e.g. wires and tubes) have received increasing attention because these highly-ordered structures possess intriguing optical and electronic properties. Here, we reported a novel and easily-processed method to fabricate a large amount of ultralong polymer/small molecule hybrid microstructures based on classical donor poly(3-hexyl)thiophene (P3HT) and acceptor 7,7,8,8-tetracyanoquinodimethane (TCNQ). This simple solution-process via evaporating mixed solutions of P3HT/TCNQ with different ratios can generate the desired 1D microstructure with lengths of up to several centimeters. The performance of field-effect transistors based on these as-fabricated microstructures indicated that the charge-transport properties can be controlled by simply adjusting the mixture ratio, resulting in p-type, ambipolar or barely non-charge transport features. Our approach would provide a new tool to understand the growth mechanism and rational control of the ratios of appropriate materials, which is instructive to enhance the performance of organic semiconductor devices.