Superfast crystalline powder synthetic strategy toward scale-up of perovskite solar cells

Commercialized perovskite solar cells (PSCs) are limited owing to the high cost of high-purity PbI2 (99.999%), raw material batch variance, and stoichiometric deviation. Here, we report a rapid antisolvent-assisted crystallization (RAC) method to speedily obtain high-grade perovskite powders from low-purity and inexpensive PbI2 (98%) raw materials. Without long-term stirring or employing any toxic antisolvent, RAC is a cost-efficient and environmentally friendly method with a high yield of over 92%. By precise characterization, the RAC method can reduce the impurities in raw materials that minimize the impurity-induced shallow-level trap density and hence the non-radiative recombination of carriers. As per the results, over 12% increase in power conversion efficiency (PCE) is obtained from low-grade raw materials, resulting in a champion PCE of 20.5% for small-area MAPbI3 PSCs and certified 18.35% for doctor-bladed 6.75-cm2 mini-module. With a reduction in material cost and a considerable increase in efficiency, RAC is a suitable alternative to the mass-produced, commercially available large-scale PSC.