The grain boundaries in thin-film perovskite solar cells are responsible for non-radiative carrier recombination, which is deleterious for the optoelectronic performance. Son et al. show how to passivate the grain boundaries by using excess CH3NH3I in the precursor solution, achieving efficiencies of 20.4%.
- Dae-Yong Son
- Jin-Wook Lee
- Nam-Gyu Park