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Direct Observation of Ferroelectric Domains in Solution-Processed CH3NH3PbI3 Perovskite Thin Films
journal contribution
posted on 2015-12-17, 04:53 authored by Yasemin Kutes, Linghan Ye, Yuanyuan Zhou, Shuping Pang, Bryan D. Huey, Nitin P. PadtureA new generation of solid-state photovoltaics
is being made possible
by the use of organometal-trihalide perovskite materials. While some
of these materials are expected to be ferroelectric, almost nothing
is known about their ferroelectric properties experimentally. Using
piezoforce microscopy (PFM), here we show unambiguously, for the first
time, the presence of ferroelectric domains in high-quality β-CH3NH3PbI3 perovskite thin films that have
been synthesized using a new solution-processing method. The size
of the ferroelectric domains is found to be about the size of the
grains (∼100 nm). We also present evidence for the reversible
switching of the ferroelectric domains by poling with DC biases. This
suggests the importance of further PFM investigations into the local
ferroelectric behavior of hybrid perovskites, in particular in situ photoeffects. Such investigations could contribute
toward the basic understanding of photovoltaic mechanisms in perovskite-based
solar cells, which is essential for the further enhancement of the
performance of these promising photovoltaics.