ABSTRACT
The photovoltaic performance of layered copper halide perovskites, in general, is limited by various factors including low absorption coefficients, the high effective mass of holes and the intrinsic low conductivity of two-dimensional perovskite structures. Copper is a nontoxic, low-cost earth abundant transition metal. The introduction of optoelectronically active cations is seen to overcome the issues stressing the importance of investigation of novel hybrid materials and making two-dimensional copper-based hybrid perovskites an ideal platform to study the further developments. Chloride was found to be essential for the material’s stability against the copper reduction and to improve the crystallization of the perovskite accompanied by a shift of the optical bandgap. Each successive inorganic perovskite sheet is shifted to give a “staggered” configuration of the layers. The distance between adjacent inorganic layers can be influenced by the length of the organic spacer alkyl or aryl, which eventually affects the compound’s dimensionality and physical properties.
