Exciton binding energies and polaron interplay in the optically excited state of organic-inorganic lead halide perovskites

Organic-inorganic lead halide perovskites (OILHPs) have been spotlighted by many researchers due to their unique features and potential for high-performance devices. One of the major obstacles with perovskites is determining the universal value for the exciton binding energy. Numerous contradictory reports in previous studies reveal a wide range of values for the exciton binding energy, spanning from a few meV to several hundred meV. Here we review different experimental and theoretical methodologies carried out to measure the exciton binding energy of OILHPs. Some of the recently explored parameters in the literature that influence exciton binding energy, like exciton dynamics and recombination, are also discussed. Besides this, prospective research initiatives in the field of exciton binding energies, with an emphasis on improving measurement precision and understanding exciton-polaron dynamics, are also highlighted. This critical understanding of exciton and polaron physics is a significant resource for researchers working on exciton-related phenomena, allowing for future breakthroughs in the design and development of efficient, high-performance devices.