Qianjin Wang,Zhilin Xiang,Peizhi Yang,Yingkai Liu,Qiuhong Tan
Metal halide perovskites recently have emerged as a promising candidate for photodetection due to their exceptional photoelectric performance. However, the high dark current in these materials has hindered their practical application to imaging. In this study, a novel halogen-mixed CsPbIBr 2 microwire photodetector that has a remarkable reduction of dark current by over 100-fold (compared to CsPbBr 3 ), along with a substantial increase in photocurrent, which yields a significantly improved on/off ratio of 6.56 × 10 4 , is developed. More importantly, the halogen-mixed perovskite photodetector exhibits enhanced photodetection performance, including a high responsivity of 133 A W −1 and a remarkable specific detectivity of 4.02 × 10 12 Jones even under ultraweak light conditions as low as 4.5 nW cm −2 . More specifically, high-resolution images are successfully obtained under ultraweak light conditions. The combined analysis of experimental results and first-principles calculation attribute the excellent performance of the CsPbIBr₂ microwire photodetector to a significant reduction in dark current by suppressing ion migration and increasing carrier effective mass, and a remarkable increase in photocurrent resulting from reduced bandgap and enhanced light absorption, as compared to CsPbBr 3 . This research represents a significant advancement in the development of high-performance 1D perovskite-based photodetectors, with promising implications for ultra-weak light imaging applications.
In this study, a temperature self-regulating solar reactor based on VO 2 thermochromic coating is demonstrated. The temperature of solar reactor can be stabilized at 68.8 °C, which is corresponded to the critical point of metal-to-insulator transition of VO 2 . By employing the solar reactor, the orthorhombic phase CsPbI 3 microwires have been synthesized through solution phase reaction route. Strong emission peaks at 490 nm and 470 nm have been observed in CsPbI 3 microwires under ultraviolet and soft X-ray excitation, respectively. The high performance photodetector based on CsPbI 3 microwire show a detectivity of 1.09 × 10 14 Jones, responsivity of 4.72 A/W, rapid rise and decay time of 0.96 and 0.93 s at 325 nm. Our results demonstrate that the temperature self-regulating solar reactor can be applied for energy-saving solution phase reactor for synthesizing high quality inorganic materials.