Lattice strain-induced high-performance low-operating-voltage organic field-effect transistors by solution-sheared organic single crystal

Abstract

Organic single-crystal semiconductors, characterized by their well-ordered long-range structure, facilitate efficient charge carrier transmission, resulting in a notable improvement in the functionality of organic optoelectronic devices, as illustrated by organic field-effect transistors (OFETs). Nevertheless, the widespread utilization of OFETs, especially in low-voltage operations (<5 V), is impeded by their suboptimal electrical performance. This work employs lattice strain engineering to enhance OFET performance utilizing inch-sized single crystals of the organic semiconductor C₈-BTBT. By modulating the shear speed during the solution shearing process, lattice strain is induced in the C₈-BTBT crystals, leading to a reduction in π–π stacking distance and thinner crystals, thereby mitigating injection resistance and enhancing charge transport capabilities. The lattice-strained single crystals demonstrate a significant enhancement in mobility, reaching 8.7 cm² V⁻¹ s⁻¹ at −3 V in low-voltage single-crystal OFETs, surpassing the highest values among similar molecules based on high-k dielectrics. Additionally, inch-scale organic single crystals display outstanding uniformity, with a 2.99% mobility coefficient of variation of 30 devices. This work underscores the potential of lattice strain engineering for large-scale, high-performance, low-power organic circuit applications, paving the way for the development of cost-effective and efficient electronic devices based on organic materials.