Proceedings of Perovskite Thin Film Photovoltaics (ABXPV17)
Publication date: 18th December 2016
A new facile preparation approach for synthesis of perovskite nanowires with different compositions is proposed using a highly reproducible method of tuning the morphology by simple varying of chemical reactants. MAPbI3 and FAPbI3 nanowires are obtained by dipping of PbI2 films into solutions of MAI and FAI dissolved in mixtures of isopropanol and dimethylformamide (DMF) and allows to control chemically the morphology of the perovskite crystals. Nanowires with different anionic composition MAPbBr3, MAPbCl3 or FAPbBr3 are obtained via an ion‑exchange in isopropanol solutions of MABr, MACl and FABr respectively.
We found that the nanowires formation sequence includes intermediate phases such as MAI-PbI2-DMF and FAI-PbI2-DMF acting as structure directing agents. The 1D shape of the adduct is preserved during the conversion to perovskite. Thus, the adducts play the role of key precursors controlling the final product morphology. Systematic investigations of the observed phase transformations and morphology features on multiple length scales revealed the effectiveness of the suggested synthetic route utilizing an original pseudomorph formation mechanism of the 1D structures to produce partly oriented films and textured layers of the nanowires via a few experimental steps. Understanding of the formation mechanism of nanowires through the adduct phases contribute to the Lewis acid‑base adduct approach for obtaining high performance materials for perovskite solar cells.
This work was supported by Ministry of Education and Science of Russian Federation, Project Number: 14.613.21.0053.