Presentation Information
[2P11]Composition dependence of the surface structure of PbBr2 ultrathin films on the Ag(111)
*Kota Tsuboi1, Junji Yuhara1 (1. Graduate School of Engineering, Nagoya University)
All-inorganic perovskite shows excellent optical performance and strong stability, making it a promising material for photovoltaic applications. CsPbBr3 ultrathin films can be prepared by co-depositing PbBr2 and CsBr through MBE, which also enables atomic-scale analysis of surface structures. In this study, PbBr2 ultrathin films were deposited on Ag(111) with varying thicknesses to investigate their surface structure. LEED patterns showed the (√3×√3)R30° and (1.18×1.18)R4.5° spots with ring-like features at low coverage. Since both (√3×√3) and (1.18×1.18) periodicities are typical growth patterns of Pb ultrathin films on Ag(111), this suggests that PbBr2 does not initially grow as a stoichiometric phase at low coverage, confirmed by XPS. Additional deposition resulted in only ring-like features, and XPS confirmed the composition as PbBr2. These results indicate that the growth mode and surface periodicity of PbBr2 ultrathin films on Ag(111) greatly depend on the amount deposited, offering valuable insights into the initial growth process of CsPbBr3 films prepared by MBE.