Stark effect in perovskite/TiO2 solar cells: evidence of local interfacial order.

Roiati, Vittoria; Mosconi, Edoardo; Listorti, Andrea; Colella, Silvia; Gigli, Giuseppe; De Angelis, Filippo · Nano Lett · 2014

basic_science · Level V

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Abstract

To unveil the mechanisms controlling photovoltaic conversion in high-performing perovskite-based mesostructured solar cells, we focus on the key role played by the mesoporous oxide/perovskite interface. We employ several spectroscopic techniques to design a complete scenario and corroborate our results with first principle density functional theory calculations. In particular Stark spectroscopy, a powerful tool allowing interface-sensitive analysis is employed to prove the existence of oriented permanent dipoles, consistent with the hypothesis of an ordered perovskite layer, close to the oxide surface. The existence of a structural order, promoted by specific local interactions, could be one of the decisive reasons for highly efficient carriers transport within perovskite films.