Lead-free vacancy-ordered double perovskites have emerged as promising materials for optoelectronic applications due to their environmentally friendly characteristics and exceptional properties.However,conventional sy...Lead-free vacancy-ordered double perovskites have emerged as promising materials for optoelectronic applications due to their environmentally friendly characteristics and exceptional properties.However,conventional synthesis methods often depend on toxic reagents and stringent conditions,limiting their large-scale synthesis and practical application.In this work,an environmentally friendly synthesis route was proposed for preparing vacancy-ordered double perovskites Cs_(2)SnX_(6)(X=Cl,Br,and I)with high crystallinity under low-temperature and ambient-pressure conditions.This method utilizes ion liquid(i.e.,1-butyl-3-methylimidazolium chloride([Bmim]Cl),1-butyl-3-methylimidazolium bromide([Bmim]Br)and 1-butyl-3-methylimidazolium iodide([Bmim]I))in combination with saturated aqueous solutions of ammonium halides as solvents,replacing traditional hydrogen halide acid or polar organic solvents.Experimental and characterization results demonstrate that the Cs_(2)SnX_(6)(X=Cl,Br,and I)possess high crystallinity,well-defined morphology,and improved thermal stability.These improvements are attributed to the hydrogen bonding interactions between ionic liquids and the perovskite precursors.Additionally,the halogen-rich environment provided by ionic liquids and ammonium halide salts facilitates defect passivation.Furthermore,this method is applicable to the synthesis of doped perovskite crystals,demonstrated by the successful synthesis of Bi-doped Cs_(2)SnCl_(6) crystals with a photoluminescence quantum efficiency of 12.73%.This study presents a novel strategy for synthesizing high-quality vacancy-ordered double perovskites and their doping or alloyed compounds.展开更多
The all-inorganic lead-free vacancy-ordered perovskite offers a promising avenue toward nontoxic and stable optoelectronic materials.Herein,we present a first-principles study of the structural stability,optical absor...The all-inorganic lead-free vacancy-ordered perovskite offers a promising avenue toward nontoxic and stable optoelectronic materials.Herein,we present a first-principles study of the structural stability,optical absorption,electronic structure,and mechanical behavior of Cs_(2)BCl_(6) compounds with B-site substitutions(B]Ge,Sn,Pb,Cr,Mo,W,Ti,Zr,and Hf).The structural analysis shows that the Cs_(2)BCl_(6) perovskite with face-centered cubes has a stable chemical environment,especially Cs_(2)HfCl_(6),Cs_(2)WCl_(6),and Cs_(2)PbCl_(6).Hf4^(+) and W4^(+) with high-energy d-state external electron configurations can further lower the valence band maximum position of the Cs_(2)BCl_(6) structures and thus increase the band gap,assisting in tuning the optical absorption and emission properties of these structures in the optoelectronic application.For the light absorption properties of Cs_(2)BCl_(6) materials,the best light absorption properties have been concluded for Ti4^(+),Cr4^(+),and Pb4^(+)-based perovskite in the visible range due to a suitable band gap.Therefore,the excellent optical absorption and electronic properties make these vacancy-ordered perovskites promising candidates for optoelectronic applications.展开更多
基金financially supported by the Beijing Natural Science Foundation,China(Nos.2254087 and 2242008)the Beijing Information Science and Technology University Foundation,China(No.1925008)Beijing Information Science and Technology University Young Faculty Support Program,China(No.YBT202411).
文摘Lead-free vacancy-ordered double perovskites have emerged as promising materials for optoelectronic applications due to their environmentally friendly characteristics and exceptional properties.However,conventional synthesis methods often depend on toxic reagents and stringent conditions,limiting their large-scale synthesis and practical application.In this work,an environmentally friendly synthesis route was proposed for preparing vacancy-ordered double perovskites Cs_(2)SnX_(6)(X=Cl,Br,and I)with high crystallinity under low-temperature and ambient-pressure conditions.This method utilizes ion liquid(i.e.,1-butyl-3-methylimidazolium chloride([Bmim]Cl),1-butyl-3-methylimidazolium bromide([Bmim]Br)and 1-butyl-3-methylimidazolium iodide([Bmim]I))in combination with saturated aqueous solutions of ammonium halides as solvents,replacing traditional hydrogen halide acid or polar organic solvents.Experimental and characterization results demonstrate that the Cs_(2)SnX_(6)(X=Cl,Br,and I)possess high crystallinity,well-defined morphology,and improved thermal stability.These improvements are attributed to the hydrogen bonding interactions between ionic liquids and the perovskite precursors.Additionally,the halogen-rich environment provided by ionic liquids and ammonium halide salts facilitates defect passivation.Furthermore,this method is applicable to the synthesis of doped perovskite crystals,demonstrated by the successful synthesis of Bi-doped Cs_(2)SnCl_(6) crystals with a photoluminescence quantum efficiency of 12.73%.This study presents a novel strategy for synthesizing high-quality vacancy-ordered double perovskites and their doping or alloyed compounds.
基金supported by the National Key Research and Development Program of China(Grant 2021YFA0715600,2018YFB2202900)the National Natural Science Foundation of China(62304171,52192610,62274127,62274125,62374128)+2 种基金the China Postdoctoral Science Foundation(2022M722500,2023TQ0255)Key Research and Development Program of Shaanxi Province(Grant 2024GX-YBXM-512)the High-Performance Computing Platform of Xidian University,Guangdong Basic and Applied Basic Research Foundation(2023A1515030084).
文摘The all-inorganic lead-free vacancy-ordered perovskite offers a promising avenue toward nontoxic and stable optoelectronic materials.Herein,we present a first-principles study of the structural stability,optical absorption,electronic structure,and mechanical behavior of Cs_(2)BCl_(6) compounds with B-site substitutions(B]Ge,Sn,Pb,Cr,Mo,W,Ti,Zr,and Hf).The structural analysis shows that the Cs_(2)BCl_(6) perovskite with face-centered cubes has a stable chemical environment,especially Cs_(2)HfCl_(6),Cs_(2)WCl_(6),and Cs_(2)PbCl_(6).Hf4^(+) and W4^(+) with high-energy d-state external electron configurations can further lower the valence band maximum position of the Cs_(2)BCl_(6) structures and thus increase the band gap,assisting in tuning the optical absorption and emission properties of these structures in the optoelectronic application.For the light absorption properties of Cs_(2)BCl_(6) materials,the best light absorption properties have been concluded for Ti4^(+),Cr4^(+),and Pb4^(+)-based perovskite in the visible range due to a suitable band gap.Therefore,the excellent optical absorption and electronic properties make these vacancy-ordered perovskites promising candidates for optoelectronic applications.
