Self-powered perovskite photon-counting detectors

• Published in: Nature (London) 2023-04, Vol.616 (7958), p.712-718
• Main Authors: Zhou, Ying, Fei, Chengbin, Uddin, Md Aslam, Zhao, Liang, Ni, Zhenyi, Huang, Jinsong
• Format: Article
• Language: English
• Subjects: 140/125; 140/146; 639/301/1005/1009; 639/624/1075/1083; Bias; Charge efficiency; Contemporary problems; Crystal defects; Defects; Efficiency; Electric fields; Energy resolution; Grain boundaries; Grain size; High temperature; Humanities and Social Sciences; Light emitting diodes; Metal halides; Morphology; multidisciplinary; optical sensors; OTHER INSTRUMENTATION; Perovskites; Photomultiplier tubes; Photons; Photovoltaic cells; Polycrystals; Radiation; Room temperature; Science; Science (multidisciplinary); Sensors; sensors and biosensors; Silicon; Solar cells; Spectrum analysis; Traps
• ISSN: 0028-0836; 1476-4687; 1476-4687
• DOI: 10.1038/s41586-023-05847-6

Metal-halide perovskites (MHPs) have been successfully exploited for converting photons to charges or vice versa in applications of solar cells, light-emitting diodes and solar fuels 1 – 3 , for which all these applications involve strong light. Here we show that self-powered polycrystalline perovskite photodetectors can rival the commercial silicon photomultipliers (SiPMs) for photon counting. The photon-counting capability of perovskite photon-counting detectors (PCDs) is mainly determined by shallow traps, despite that deep traps also limit charge-collection efficiency. Two shallow traps with energy depth of 5.8 ± 0.8 millielectronvolts (meV) and 57.2 ± 0.1 meV are identified in polycrystalline methylammonium lead triiodide, which mainly stay at grain boundaries and the surface, respectively. We show that these shallow traps can be reduced by grain-size enhancement and surface passivation using diphenyl sulfide, respectively. It greatly suppresses dark count rate (DCR) from >20,000 counts per second per square millimetre (cps mm −2 ) to 2 cps mm −2 at room temperature, enabling much better response to weak light than SiPMs. The perovskite PCDs can collect γ-ray spectra with better energy resolution than SiPMs and maintain performance at high temperatures up to 85 °C. The zero-bias operation of perovskite detectors enables no drift of noise and detection property. This study opens a new application of photon counting for perovskites that uses their unique defect properties. Suppression of shallow traps responsible for dark count rates in polycrystalline methylammonium lead triiodide using diphenyl sulfide enables the production of metal-halide perovskite photon-counting detectors that allow sensitive detection of γ-ray spectra.