Proceedings of nanoGe International Conference on Perovskite Solar Cells, Photonics and Optoelectronics (NIPHO19)
DOI: https://doi.org/10.29363/nanoge.nipho.2019.051
Publication date: 21st November 2018
Perovskite solar cells based on methylammonium lead iodide (CH3NH3PbI3) and related materials have emerged as an exciting development for next generation photovoltaic technologies. Solar cells based on them have achieved impressive energy conversion efficiencies, but their stability is still limited. Understanding degradation mechanisms in such materials is key to developing strategies to increase their lifetime. The present work reports on the nanoscale characterization of perovskite photovoltaic films with respect to their stability and degradation mechanisms. We investigated the local conductance and surface potential variation of perovskite films at the nanoscale using conducting atomic force microscopy (CAFM) and Kelvin probe force microscopy (KPFM). CAFM measurements revealed that the current is larger at grain boundaries. CPD differences between GBs and grains is almost same which suggest the ability of charge carriers capture is almost same in grains and GBs. We investigated the effect of sunlight exposure on the nano-scale conductance and surface potential of perovskite thin films towards better understanding of photo-induced degradation mechanisms.
We thank Prof. D. Feuerman and Prof. J. Gordon for use of their solar concentration lab.