Organic photodetectors based on pentacene single crystals with fast response and flexibility

Abstract

Organic single crystals (OSCs) have attracted increasing interest in advanced optoelectronic devices, in particular for flexible and wearable devices, due to their high carrier mobility and intrinsic mechanical flexibility. Currently, remarkable electrical performances have been realized in OSCs, while the photoelectronic performances of the device have not been fully optimized and the response speed of the device is also barely satisfactory. Here, we demonstrate a high-performance organic phototransistor based on the pentacene single crystals, which are grown using a facile in-air sublimation method. Under light illumination, the rise and decay times of the device drop as low as ∼100 and 150 μs, respectively, which are competitive in the field of organic phototransistors. Utilizing its outstanding response time, we demonstrate high-resolution image recognition using high-frequency modulated 532 and 658 nm optical excitation. In addition, its remarkable mechanical flexibility is also verified in a two-terminal device, which retained excellent electrical conductivity and stable light detection even after 500 bending cycles. The results suggest that high-quality single crystals are a promising platform for future high-performance flexible and wearable optoelectronic devices.