Committee

• Prof. Juan-Pablo Correa-Baena – School of MSE, Georgia Institute of Technology (advisor)
• Prof. Natalie Stingelin – Schools of MSE & ChBE, Georgia Institute of Technology
• Prof. Emma Hu – School of MSE, Georgia Institute of Technology
• Prof. Vinod Menon – School of Physics, City University of New York
• Prof. Carlos Silva-Acuña – School of Physics, Université de Montréal
• Prof. Ajay Ram Srimath Kandada – School of Physics, Wake Forest University

Abstract

Low-dimensional halide perovskites are naturally occurring quantum-well structures with confined excitons. Due to their tunable emission bandwidth, large exciton binding energies, strong oscillator strengths, and low non-radiative recombination rates, they offer an ideal platform to study light-matter interaction. However, the relationship between structural modifications and changes in excited states and their coupling with light remains poorly understood. This thesis aims to gain a further understanding of how the manipulation of crystal structure and chemical composition of low-dimensional perovskites can tailor their optoelectronic properties. In Chapter 1, we study pure two-dimensional (2D) perovskites in the strong light-matter coupling regime, where excitonic transitions in a material placed inside a microcavity, hybridize with modes of a confined electromagnetic field, yielding two energetically distinct states: the upper and lower polariton modes. Here, we systematically examine the interplay between the emission from the material’s exciton reservoir and the population of the lower polariton, gaining insights into how the spectral features of the emission of 2D perovskites affect polariton relaxation processes. In Chapter 2 I propose to study the effect of confinement on the optical response of 2D perovskites by tracking changes in the material's spectral features induced by modifications to the interplanar distance of these materials. Finally, in Chapter 3, I propose to explore how adjusting the number of organic to inorganic layers in low-dimensional perovskites influences their optical response. Through rigorous structural characterizations and vapor deposition techniques, we will fabricate phase-pure perovskites with a desired proportion of organic to inorganic layers, transitioning from pure 2D perovskites to higher-dimensional quasi-2D perovskites.