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.