Cs_(2)TiI_(6):A potential lead-free all-inorganic perovskite material for ultrahigh-performance photovoltaic cells and alpha-particle detection

The lead contamination and long-term stability are the two important problems limiting the commercialization of organic–inorganic lead halide perovskites.In this study,through an innovative multi-scale simulation strategy based on the first-principle calculations coupling with drift-diffusion model and Monte Carlo method,a new discovery is shed on the vacancy-ordered double perovskite Cs_(2)TiI_(6),a potential nontoxic and stable perovskite material for high-performance solar cell andα-particle detection.The excellent photon absorption character and ultrahigh carrier mobility(μn=2.26×10^(4)cm^(2)/Vs,μp=7.38×10^(3)cm^(2)/Vs)of Cs_(2)TiI_(6)induce ultrahigh power conversion efficiency(PCE)for both single-junction solar cell(22.70%)and monolithic all-perovskite tandem solar cell(26.87%).Moreover,the outstanding device performance can be remained even in high energy charge particle detection(α-particle)with excellent charge collection efficiency(CCE=99.2%)and mobility-lifetime product(μτh=1×10^(–3)cm^(2)/V).Furthermore,to our surprise,the solar cell andα-particle detector based on Cs_(2)TiI_(6)material are able to withstand ultrahigh fluence proton beam up to 1013 and 1015 p/cm2 respectively,which strongly suggests that semiconductor devices based on Cs_(2)TiI_(6)material are able to apply in the astrospace.The multi-scale simulation connecting from material to device reveals that Cs_(2)TiI_(6)perovskite has the great potential for photovoltaic cells,α-particle detection and even their space application.