Single Crystal Microwires of p ‐DTS(FBTTh 2 ) 2 and Their Use in the Fabrication of Field‐Effect Transistors and Photodetectors

Single crystal microwires of a well-studied organic semiconductor used in organic solar cells, namely p-DTS(FBTTh2)2, are prepared via a self-assembly method in solution. The high level of intermolecular organization in the single crystals facilitates migration of charges, relative to solution-processed films, and provides insight into the intrinsic charge transport properties of p-DTS(FBTTh2)2. Field-effect transistors based on the microwires can achieve hole mobilities on the order of ≈1.8 cm2 V−1 s−1. Furthermore, these microwires show photoresponsive electrical characteristics and can act as photoswitches, with switch ratios over 1000. These experimental results are interpreted using theoretical simulations using an atomistic density functional theory approach. Based on the lattice organization, intermolecular couplings and reorganization energies are calculated, and hole mobilities for comparison with experimental measurements are further estimated. These results demonstrate a unique example of the optoelectronic applications of p-DTS(FBTTh2)2 microwires.