Interfacial Engineering of High-Performance, Solution-Processed Sb2S3 Phototransistors

Antimony sulfide, as a binary chalcogenide, has attracted great attention in the field of optoelectronics in recent years, particularly in photovoltaics, because of its striking merits such as earth elements abundance, excellent stability, chemical versatility, and solution processability. With the rapid development of fabrication techniques and device engineering, the device performance of Sb₂S₃ solar cells has experienced an unprecedented success. However, photodetectors based on Sb₂S₃ were barely reported, especially based on the transistor configuration. In this work, we prepared high quality Sb₂S₃ thin films via a sol-gel method, and Sb₂S₃ thin films were deposited on zinc-tin oxide based field-effect transistors. Furthermore, an additional electron transport layer was inserted between the Sb₂S₃ layers and the zinc-tin oxide channels and archived high-performance phototransistors with proper interfacial engineering. The optimized devices exhibited extremely high photosensitivity (10⁶), low dark current (∼10 pA) and noise (∼11 fA Hz^-1/2), high detectivity (1 × 10¹³ Jones), and superior device stability, indicating great potential for next generation solution-processed photodetectors.