Monitoring the formation of surface-enriched PbI2 in atmospherically treated perovskite films using neutron reflectivity

Metal halide perovskites have enabled remarkable advancements in low-cost, high-performance optoelectronics, however their performance potential is restricted by an incomplete understanding of structural and compositional changes that take place due to sample surface passivation treatments in different environments. Using neutron reflectivity we will develop this research area by measuring in-situ the kinetics of compositional changes at the surface of perovskite films during sample exposure to a range of atmospheres, correlating the results with simultaneous photoluminescence measurements that provide a measure of semiconductor film quality. This state-of-the-art study will be used alongside complementary studies at Cambridge and our collaborators to construct new structure-property relationships that will be used to advance perovskites as a class of semiconductor that functions at its