Laser-Generated Nanocrystals in Perovskite: Universal Embedding of Ligand-Free and Sub-10 nm Nanocrystals in Solution-Processed Metal Halide Perovskite Films for Effectively Modulated Optoelectronic Performance

Regulating the chemical/physical features of solution processed metal halide perovskite films by integrating sub-10 nm nanocrystals is a highly promising strategy to advance their outstanding optoelectronic performance. However, significant challenges remain for the universal embedding of the well-defined nanocrystals in the film matrix. By generating nanocrystals in desired solvents via pulsed laser irradiation in liquid, the authors demonstrate the effective decoration of sub-10 nm nanocrystals in perovskite films for enhanced optoelectronic performance. It is believed that this improved performance is due to the modification of the widely adopted "antisolvent" to a novel "anti-colloidal-solution" (ACS). Exemplified by a typical ACS; carbon dots in chlorobenzene, its encouraging superiority in regulating, not only the films morphology, but also the electronic structure, is demonstrated. This results in perovskite solar cells with a champion efficiency of 21.41% as well as a pronounced stability over 5000 h in relative humidity of 40%. The capability of nanocrystal embedding for boosted photovoltaic performance is further exploited by employing other laser generated ACSs. Such a strategy may open up a route to regulating hybrid perovskite film performance via nanocrystal embedding for photovoltaics or even beyond optoelectronic applications.