1 research outputs found
Probing the Reactivity of ZnO with Perovskite Precursors
To achieve more stable
and efficient metal halide perovskite devices,
optimization of charge transport materials and their interfaces with
perovskites is crucial. ZnO on paper would make an ideal electron
transport layer in perovskite devices. This metal oxide has a large
bandgap, making it transparent to visible light; it can be easily
n-type doped, has a decent electron mobility, and is thought to be
chemically relatively inert. However, in combination with perovskites,
ZnO has turned out to be a source of instability, rapidly degrading
the performance of devices. In this work, we provide a comprehensive
experimental and computational study of the interaction between the
most common organic perovskite precursors and the surface of ZnO,
with the aim of understanding the observed instability. Using X-ray
photoelectron spectroscopy, we find a complete degradation of the
precursors in contact with ZnO and the formation of volatile species
as well as new surface bonds. Our computational work reveals that
different pristine and defected surface terminations of ZnO facilitate
the decomposition of the perovskite precursor molecules, mainly through
deprotonation, making the deposition of the latter on those surfaces
impossible without the use of passivation