Design and Fabrication of Perovskite Micro-Cavity Lasers

Abstract

Over the past several years, research of methylammonium trihalide perovskite solar cells has led to a rapid increase in the efficiency of single p-n junction perovskite solar cells, from 6.5% in 2012 to 22.1% in 2016. Favorable optical properties make CH3NH3PbI3 perovskite a promising candidate for performing at the Shockley-Queisser limit; the theoretical maximum efficiency of single p-n junction solar cells, and a commonly cited goal for photovoltaics researchers. To operate at this limit, the gain material must exhibit purely radiative recombination. Thus, research in photovoltaics is actively trying to improve the quality of thin-film perovskite in order to maximize its efficiency not only as a light absorber, but as a light emitting material. A high-quality optical micro-cavity requires patterning of microstructures, which is made difficult by perovskite’s sensitivity to chemicals used in conventional fabrication processes. This thesis describes three designs of a perovskite laser: 1) a silicon nitride photonic crystal cavity coupled to a perovskite gain medium, 2) whispering-gallery mode lasers made by chemically reflowing perovskite, and 3) an electrically-pumped distributed feedback laser.