Synthesis and luminescence properties of lead-halide based organic–inorganic layered perovskite compounds (CnH2n+1NH3)2PbI4 (n=4, 5, 7, 8 and 9)
作者:Nobuaki Kitazawa、Masami Aono、Yoshihisa Watanabe
DOI:10.1016/j.jpcs.2011.08.029
日期:2011.12
This paper describes the synthesis and characterization of organic inorganic layered perovskite compounds, (CnH2n+1NH3)(2)PbI4 (n=4, 5, 7, 8 and 9). The effect of the number of carbon atoms on luminescence properties has been examined. Thin films of microcrystalline (CnH2n+1NH3)(2)PbI4 fabricated by spin-coating are highly oriented, with the c-axis perpendicular to the substrate surface. Temperature-dependent optical absorption spectra reveal that (CnH2n+1NH3)(2)PbI4 films (n = 4, 7, 8 and 9) show the structural phase transitions. The excitonic structures of (CnH2n+1NH3)(2)PbI4 vary with the number of carbon atoms of the alkyl chain length. At low temperatures below 100 K, the lowest-energy free-exciton band of (CnH2n+1NH3)(2)PbI4 (n = 7, 8 and 9) split into three fine-structure levels. In contrast to (CnH2n+1NH3)(2)PbBr4 films, (CnH2n+1NH3)(2)PbI4 (n = 7, 8 and 9) shows no triplet exciton emission, but it shows the Stokes-shifted emission from bound excitons. (C) 2011 Elsevier Ltd. All rights reserved.