N-type organic phototransistors based on PTCDA single crystals for broadband imaging

Abstract

Organic single crystals (OSCs) herald new opportunities for the fabrication of advanced optoelectronic devices, especially for flexible and wearable devices, owing to their unique material properties including high mobility and intrinsic flexibility. Up to now, though the electrical characteristics have been a breakthrough in OSCs, the devices have not been fully optimized for inherent photoelectric properties, and their photoresponse characteristics are also scarcely satisfactory, especially for the n-type organic materials. In this work, we prepared a high-performance organic phototransistor employing the air-stable PTCDA single crystal, grown by a simple microspacing in-air sublimation technique. The responsivity and photosensitivity of the device can reach up to 180 A/W and 103 for 532 nm illumination, with also a good response speed (rise and decay times less than 1 and 2 ms). In addition, we demonstrated several high-resolution imaging in this organic transistor. Our results demonstrated that the high-quality n-type organic single crystal is also a promising candidate for future high-performance photodetector and imaging applications.