Ultrafast and\nSensitive Photon Counters Based on Solution-Processed\nChalcogenide Thin Films for Multiple Applications

Due to their excellent optoelectronic properties and\nmaterial stability,\nchalcogenide semiconductors have been successfully introduced for\nphotovoltaics, photodetectors, and photocatalysis. However, current\nchalcogenide-based photodetectors are still struggling to achieve\nboth low noise and high sensitivity simultaneously, mainly limited\nby the poor film quality, which is not ideal for practical applications,\nparticularly for weak light detection and photon counting. Here we\nfabricated high quality Sb<sub>2</sub>S<sub>3</sub> and antimony bismuth\nsulfide thin films via solution-process and achieved photodiodes with\nexcellent performance. Compared to Sb<sub>2</sub>S<sub>3</sub>, the\noptimized antimony bismuth sulfide detectors exhibit excellent photon\ncounting capability, including high bias voltage tolerance, low noise\nand dark count rate at −10 V, high sensitivity, fast response\n(∼180 ns), and superior stability. More importantly, these\ndevices demonstrated great potential for multiple applications, such\nas photoluminescence lifetime spectroscopy, optical communication,\nwastewater monitoring, and heart rate detection.