Quasi 2D Perovskite Laser
The So and Gundogdu groups demonstrated a highly efficient, low threshold optically pumped perovskite laser. In quasi 2D perovskites, exciton funneling into low energy 3D domains functions as the gain medium. Here we studied solution engineering methods to optimize the exciton funneling kinetics. We showed that structures with optimized domain alignment lead to ultrafast exciton funneling and low threshold amplified spontaneous emission. We further developed a top down approach to grow distributed-feedback (DFB) structures. In solution processed DFB lasers, challenges include the tuning of the gain medium thickness and matching the DFB grating spectrum to the gain spectrum of the material. For this purpose, the So group developed a top-down method that enables precision control of the cavity mode for efficient laser device processing. We finally studied the quantum phase transition of an exciton population ensemble into a Dicke superradiant state. We discovered that hybrid perovskites can exhibit superfluorescence at unprecedently high temperatures, making these materials suitable for emerging quantum technologies.