Enhanced performance of perovskite solar cells by modulating the Lewis acid base reaction.
The Lewis acid base reaction between PbI2 and solvent molecules is popular in fabricating PbI2 films by a two step method for making perovskite solar cells. Here, we control the microstructure of PbI2 films through modulating the Lewis acid base reaction by adding a small amount of N methyl pyrrolidone into PbI2/DMF solution. PbI2 films with excellent crystallinity and full coverage are fabricated by spin coating the mixed solution on the substrate, which leads to high quality perovskite layers with low recombination rate and high efficiency for carrier transfer. As a result, the power conversion efficiency of the best perovskite solar cells increases from 13.3% to 17.5%
Nanoscale