Fabrication and application of porous organic single-crystal films in highly sensitive gas sensors

Gas sensors based on organic semiconductor materials (OSCs) have garnered significant attention due to their cost-effectiveness and ability to operate efficiently at room temperature. However, the performance of these sensors is often constrained by the grain boundaries and defects inherent in polycrystalline films typically produced by conventional methods. In this study, a novel approach was developed for fabricating large-area porous organic single-crystal films. Hydrophobic lattice structures were engineered on hydrophilic substrate surfaces, facilitating the growth of 2,7-dioctyl[1]benzothieno[3,2-b][1]benzothiophene (C8-BTBT) molecules by micro-spacing sublimation with liquid crystal properties. These hydrophobic lattice structures function as thermal stress release sites during the film cooling process, enabling the formation of organic single-crystal films with precisely controlled pore locations and sizes. The resulting porous films demonstrate electrical properties on stripes with those achieved through growing on bare silicon substrates, yet exhibit enhanced sensitivity, faster response times, and a lower detection limit when used as active layers in gas sensors. This technique offers a promising pathway for advancing high-performance organic gas sensors toward industrial application.