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.

Additional Materials