Systematic Studies on Chain Lengths, Halide Species, and Well Thicknesses for Lead Halide Layered Perovskite Thin Films

Abstract
Two-dimensional layered perovskite compounds, (CnH2n+1NH3)2(CH3NH3)m−1PbmX3m+1 (n = 2, 3, 4, 6, and 10; X = Cl, Br, and I; m = 1, 2, and 3) were systematically prepared. The influences of the barrier-size, halide species, and well thickness of the perovskite thin films on the quantum confinement structures were investigated. The layered perovskite films showed a strong and clear absorption peak due to excitons confined in inorganic quantum-wells. The exciton peak shifted to lower energy as the halide species was changed from Cl to Br and I. Furthermore, fine multilayer perovskite compound films were prepared by varying the spin-coating conditions.