Synthesis and Evaluation of Novel A-Site Ligands for 2D Perovskites for Use in Studying Charge and Energy Transfer in Quantum-Confined Systems

Abstract

In recent years, 3D perovskites have become the focus of many research studies, given their unique charge transfer and electronic properties. Perovskites have been used to synthesize thin film organic solar cells, and their certified efficiencies now exceed that of multicrystalline Si. However, very little research has been conducted into 2D perovskites, which can provide insight into charge and energy transfers that occur in quantum-confined systems. Specifically, 2D perovskites have a large interfacial volume, which could allow for charge and energy transfer to occur via resonance, intersystem crossing, and exciton-charge interactions. Exciton-charge interactions in particular have proved problematic in organic LEDs, and 2D perovskites would theoretically allow us to obviate this issue. Studying these would require creating alternating layers of organic molecules and inorganic perovskites in order to focus on quantum wells. Synthesizing 2D perovskites requires a specific type of A-site ligand, as they need to be heavily conjugated and contain linker chains. At the same time, we need to make sure we control the exciton binding energy and that the ligands can bind to the octahedral inorganic perovskites. This thesis examines the synthesis of novel A-site ligands for 2D perovskites and characterizes the effectiveness of their charge transfer properties. The effectiveness characterization is done in conjunction with Prof. Barry Rand’s group in the Electrical Engineering Department. In addition, this thesis contains a chapter analyzing the cost-effectiveness of perovskites, specifically the cost of procuring metals for use in 3D and 2D perovskites and comparing this cost to existing materials used in LEDs and organic solar cells. This thesis will also examine the future financial outlook for perovskites and attempt to determine cost-effective commercial opportunities based on current economic trends.