Decoupling the Effects of Interfacial Chemistry and Grain Size in Perovskite Stability

This work reports a materials and degradation study of the ubiquitous perovskite absorber methylammonium lead iodide (MAPbI3). MAPbI3 films were solution deposited on systematically varied glass/metal oxide (MO), transparent conductive oxide (TCO)/MO, and TCO/organofunctional silane stacks. Results show that the underlying layers affect the absorber film morphology, and stability under exposure to heat and humidity. Critically, the use of an organofunctional silane modifier can decrease the grain size, but increase the stability of MAPBI3 deposited on indium tin oxide (ITO). Further, non-adjacent layers can also affect the stability of the perovskite films.