High-throughput Screening And Optoelectronic Modulation Of Leadfree Halide Bimetallic Perovskite Materials

In recent years,perovskite family(ABX3)materials have attracted widespread attention due to their excellent photoelectric performance in the field of solar cells.Since Kojima and others first reported the power conversion efficiency(PCE)of methylammonium lead halide perovskites at～3%in 2009,the PCE of perovskite solar cells has achieved leapfrog development in just a decade.Currently,perovskite solar cells are functionally comparable to traditional poly crystalline silicon and cadmium telluride solar cells,and are expected to become the energy carriers for the next generation of renewable energy.However,due to their insufficient stability and the drawbacks of heavy metal toxicity,there is still a long way to go before practical application.Therefore,finding alternative lead-free inorganic systems to overcome the impacts of stability and toxicity is a very meaningful research direction.In this paper,we construct a series of non-toxic double perovskite materials based on the structure of lead-based perovskites.We screen their stability and efficiency through certain criteria,including tolerance factors,bandgaps,decomposition enthalpies,effective masses,and efficiency.We ultimately identify several feasible lead-free perovskite materials and compute and predict their optoelectronic properties,demonstrating new avenues for the design of novel organic/inorganic functional materials.Specifically,we construct structures of pure inorganic and inorganic-organic hybrid double perovskites.We finally select four inorganic double perovskites Cs2AgInBr6,Rb2AgSbBr6,Cs2AuBiCl6,and Cs2AgSbBr6;and three organic-inorganic hybrid double perovskites FA2AgAuBr6,MA2AgAuBr6,and MA2AgAuCl6.They exhibit suitable bandgaps,low carrier effective masses,and outstanding photovoltaic absorption performance,with the potential to replace lead-containing perovskites as highly efficient absorber layers in solar cells.Additionally,we manipulate the bandgap of inorganic double perovskites by utilizing quantum confinement effects and then study the properties of 112 materials.In total,we screen four single-layer halide double perovskite materials suitable for application in solar cells,which are the tetragonal phase Cs2AgAuCl6 and Rb2AgAuF6,and the cubic phase Cs2AgAuF6 and Rb2AgAuF6.Our work provides valuable theoretical guidance for the experimental synthesis and preparation of these materials.