First-Principles Study on Photoelectric Properties of Lead-Free Double Perovskites A2AgIrX6(A=Cs,Rb;X=Cl,Br)
Lead halide perovskites have become excellent semiconductor materials widely used in the optoelectronics field due to their suitable direct bandgap,excellent carrier mobility,and high optical absorption.However,their poor stability and the presence of toxic element Pb have limited their application in the optoelectronics field.Therefore,researchers are currently facing the challenge of finding non-toxic and efficient perovskite materials.Lead-free halide double perovskite materials,due to their stable performance and non-toxic and efficient properties,are expected to become poten-tial application materials in the optoelectronics field.Here,we have systematically investigated the electronic structure and optical properties of double perovskites A2AgIrX6(A=Cs,Rb;X=Cl,Br)based on the density functional theory(DFT).The tolerance factor,octahedral factor,formation energy,and molecular dynamics simulations indicate that A2AgIrX6 double perovskites possess excellent structural stability and thermodynamic stability,and are direct bandgap semiconductor(Eg=1.73～2.30 eV)with outstanding light absorption properties in the visible light range.The absorption coefficient of all double perovskites in the visible-light region can reach～105 cm-1,which can effectively improve the utilization efficiency of solar energy and promote the efficiency of photo-electric conversion.The research indicates that A2 AgIrX6 is a potential material for light detection and optoelectronic memory.The research findings can provide theoretical guidance for the experi-mental synthesis of optoelectronic detector materials with high carrier mobility and strong light absorption capability.
NETL
NSTL
万方数据
