Despite the rapid rise in the performance of a variety of perovskite optoelectronic devices with vertical charge transport, the effects of ion migration remain a common and longstanding Achilles' heel limiting the long-term operational stability of lead halide perovskite devices, although there is still limited understanding of the impact of tin (Sn) substitution on the ion dynamics of lead (pb) halide perovskites.
Professor Saiful Islam and collaborators from the Universities of Cambridge, Bath, Loughborough and the Indian Institute of Technology Delhi and HBNI in Jatni, employed scan-rate-dependent current-voltage measurements on Pb and mixed Pb-Sn perovskite solar cells to show that short circuit current losses at lower scan rates, which can be traced to the presence of mobile ions, are present in both kinds of perovskites.