摘要
The lead-free perovskites Cs_(3)B_(2)X_(9)(B=Sb,Bi;X=Cl,Br,I)as the popular photoelectric materials have excellent optical properties with lower toxicity.In this study,we systematically investigate the stable monolayer Cs_(3)B_(2)X_(9)and bilayer vertical heterostructure Cs_(3)B_(2)X_(9)/Cs3B02X9(B,B0=Sb,Bi;X=Cl,Br,I)via first-principles simulations.By exploring the electrical structures and band edge positions,we find the band gap reduction and the band type transition in the heterostructure Cs_(3)B_(2)X_(9)/Cs3B02X9 due to the charge transfer between layers.Furthermore,the results of optical properties reveal light absorption from the visible light to UV region,especially monolayer Cs3Sb2I9 and heterostructure Cs3Sb2I9/Cs3Bi2I9,which have absorption peaks in the visible light region,leading to the possibility of photocatalytic water splitting.These results provide insights for more two-dimensional semiconductors applied in the optoelectronic and photocatalytic fields.
作者
龙耀文
张红
程新路
Yaowen Long;Hong Zhang;Xinlu Cheng(College of Physics,Sichuan University,Chengdu 610065,China;Key Laboratory of High Energy Density Physics and Technology(Ministry of Education),Sichuan University,Chengdu 610065,China;Institute of Atomic and Molecular Physics,Sichuan University,Chengdu 610065,China)
基金
supported by the National Key R&D Program of China(Grant No.2017YFA0303600)
the National Natural Science Foundation of China(Grant No.11974253)
the Science Specialty Program of Sichuan University(Grand No.2020SCUNL210)。