Temperature-Dependent Structure-Property Relationship in [(4AMTP)PbBr2]2PbBr4 Single Crystal

Abstract

Metal halide perovskites are known for their excellent optoelectronic properties. 2D (layered) metal halide perovskite has impressive structural diversity. Due to its structural diversity and facile synthesis, they are considered a good candidate for synthesizing novel 2D halide perovskites with multiple functionalities. Based on the same principle, we have prepared centimetre sized crystals of [(4AMTP)PbBr2]2PbBr4 2D perovskite having hybrid A-site cation using reported antisolvent method. It is expected that the hybrid A-site cation layer, either directly, or indirectly through structural modification, would affect the optoelectronic properties of [(4AMTP)PbBr2]2PbBr4. So, the exploration of the temperature-dependent structure-property relationship of this newly discovered 2D perovskites is highly desired. Since the full chemical space for this structure-type is not yet revealed, the major emphasis of this thesis is devoted to establish structure-property relationship of this newly discovered 2D perovskite. Single crystal x-ray diffraction, variable temperature powder x-ray diffraction, thermogravimetric analysis, and differential scanning calorimetry measurements has been carried out to understand role of hybrid cation in determining temperature dependent structural parameters and phase transition. Further monoclinic phase of [(4AMTP)PbBr2]2PbBr4 2D perovskite has been studied for their optical properties at cryogenic temperatures to determine possibility of long lived dark excitonic emission that has been generalized for thin films of all monoclinic phase 2D perovskites. The obtained results have been described in terms of three state model established in prior literatures.