摘要：Recently,the newly booming metal halide perovskites have attracted extensive attention worldwide due to their outstanding optoelectronic performance,and are expected to be ideal candidates for photodetectors(PDs).However,there is still lack of perovskite PDs-based imaging devices coming into commercialization stage,due to some practical reasons including toxicity brought by lead-based perovskites and the large light current *** this paper,for the first time we fabricate a lead-free Cs3Bi2Br9 perovskite PD,and build a prototype of this perovskite PD-based imaging system with diffuse reflection imaging ***,we propose a new parameter F related to light current fluctuation to evaluate imaging performance of a PD especially for weak diffuse light condition,and prove its usability by comparison of unoptimized lead-free Cs3Bi2Br9 perovskite PD and atomic layer deposition(ALD)optimized Cs3Bi2 Br9 ***-optimization can improve the quality of perovskite film and suppress the dark current and current ***,we obtain satisfactory diffuse reflection images of 2D and 3D objects with wide dynamic ***,the ALD-optimized Cs3Bi2Br9PD has addressed two major concerns about perovskite PDs-based imaging devices,that may extend application of perovskite materials and improve imaging quality.

摘要：The underlying spin-related mechanism remains unclear,and the rational manipulation of spin states is challenging due to various spin configurations under different coordination ***,it is urgent to study spin-dependent oxygen evolution reaction(OER)performance through a controllable ***,we adopt a topochemical reaction method to synthesize a series of selenides with eg occupancies ranging from 1.67 to *** process begins with monoclinic-CoSeO_(3),featuring a distinct laminar structure and Co-O6 *** topochemical reaction induces significant changes in the crystal field's intensity,leading to spin state *** transitions are driven by topological changes from a Co-O-Se-O-Co to a Co-Se-Co configuration,strengthening the crystalline field and reducing eg orbital *** reconfiguration of spin states shifts the rate-determining step from desorption to adsorption for both OER and the hydrogen evolution reaction(HER),reducing the potential-determined step barrier and enhancing overall catalytic *** a result,the synthesized cobalt selenide exhibits significantly enhanced adsorption *** material demonstrates impressive overpotentials of 35 mV for HER,250 mV for OER,and 270 mV for overall water splitting,indicating superior catalytic activity and ***,a negative relation between eg filling and OER catalytic performance confirms the spin-dependent nature of *** findings provide crucial insights into the role of spin state transitions in catalytic performance.