0D structured Cs₄PbI₆ single crystals for highly performance UV photodetection

In this work, a high-performance and stable UV photodetector is reported that is based on solution-processed lead bulk Cs₄PbI₆ single crystals. The Cs₄PbI₆ single crystals are demonstrated with unique 0D structural and high visible transparent with the wide optical bandgap at 3.46 eV. The crystals exhibit excellent electrical properties with a large μτ value of 9.5 × 10^-4 cm² V^-1 and a low trap density of 1.7 × 10¹⁰ cm^-3. Further, a symmetrical Au-semiconductor-Au structured ultraviolet photodetector based on Cs₄PbI₆ single crystals has been achieved. The device has been demonstrated with good UV detection performances at 1 V bias: low dark current density of 63.6 nA cm^-2, the ratio of the photocurrent to the dark current was about 728 times, fast time profile (response time and recovery time are 11.65 and 12.80 μs, respectively), high UV response (responsivity of 5.07 mA W^-1). In addition, the device has good environmental stability under the temperature from 303 K to 404 K and air. This work proves that Cs₄PbI₆ is a competitive candidate for ultraviolet photon detectors with high detection performance and strong environmental stability.