Polaron mediated long-lived bandedge carriers in lead halide perovskite nanocrystals

The lead halide perovskites (LHPs), (APbX3, A = Cs, MA, or FA and X = I, Br, or Cl) are well known for moderate carrier mobility, static and dynamic structural disorder. Despite this, LHPs exhibited unusual fascinating properties, including long carrier lifetime, diffusion length and better defect tolerance. This aroused great interest in scientific community to exploit many-body interactions in LHP. It is neither free carrier nor exciton, however, large polaron that derive and manipulate many-body interaction in these systems. These large polarons screens the coulombic potential which is responsible for tuning the exotic properties for optoelectronic applications. A polaron is a carrier dressed with polarized soft lattice, formed due to structural distortion in inorganic framework PbX3. We employ ultrafast pump-probe spectroscopy to study the dynamics of polaron in FAPbI3 nanocrystals (NCs) at low fluence targeting its practical commercialization in solar cells.