Metal Halide Perovskites for Blue and Near-Infrared Optically Pumped Lasers

Abstract

Perovskites have been researched as materials with desirable properties for electro-optical applications, such as a laser that utilizes the perovskite as a gain medium for lasing. Through experimental and theoretical studies, researchers have made perovskite lasers available for a large part of the visible spectrum. Moreover, tunable perovskite lasing over a wide spectrum of wavelengths has been achieved by controlling the makeup and stoichiometry of the perovskite gain material. However, lasing has not been achieved in the near-infrared (~900 nm) and the blue (~400 nm) ends of the spectrum. Thus, to address these gaps in perovskite lasing, perovskite thin films have been fabricated in the hopes of achieving tunable lasing in these spectrums. To achieve lasing, the perovskite precursor solution can be spun onto a grating and optically pumped. Furthermore, to validate the adequacy of a perovskite thin film for lasing, it is optically pumped with increased excitation intensity and tested for photoluminescence and amplified spontaneous emission. Findings are presented in this thesis for various methods and experiments used to fabricate thin-film perovskites and evaluate their performance and adequacy for lasing in the blue and near-infrared spectral regions. Ultimately, amplified spontaneous emission was not achieved from any of the perovskite thin films studied. However, observations (e.g., the presence of mid-gap trap states and oxidation) and experimental results were obtained which will aid future research of perovskite lasers. Photoluminescent emission was achieved for MAPbSnI3 and MAPbCl3 (MA: methylammonium) thin films, which emitted in the near-infrared and blue, respectively. Additionally, experiments were carried out to explore and improve the performance of the perovskites used to achieve photoluminescent emission.