Single Crystals: The Next Big Wave of Perovskite Optoelectronics

Contemporary advancements in perovskite semiconductors are visibly impacting the progress of light conversion applications. These alluring photo absorbers have gained wide consideration, because of their simple processing and striking optoelectronic properties. Although polycrystalline perovskite thin films exhibit phenomenal performance in energy-harvesting devices, they suffer from severe instabilities arising from morphological disorder and surface degradation under ambient conditions. Recent progress in perovskite single-crystals, which, in theory should outperform their polycrystalline thin-film counterparts, has been demonstrated to surmount these challenges, because of the exceptional optoelectronic properties, such as low trap density, high mobility, low intrinsic carrier concentration and long carrier diffusion length. However, most of the growth approaches used for single-crystal syntheses produce very thick crystals and subsequently, the related optoelectronic applications are very limited. Given the potential of perovskite single crystals, to break a new path for perovskite optoelectronic devices relies on understanding sustainable issues arising from interfacial/integration losses and developing passivation strategies to achieve performance parity in an open ambient atmosphere. Therefore, the current review provides a comprehensive overview of the advantages, limitations, and challenges associated with growth methods of single-crystals and their chemical stability, device configurations, photophysics, charge carrier dynamics, and photovoltaic applications.