Channeling Exciton Migration into Electron Transfer in Formamidinium Lead Bromide Perovskite Nanocrystal/Fullerene Composites.

Nair, Vijayakumar C.; Muthu, Chinnadurai; Rogach, Andrey L.; Kohara, Reiko; Biju, Vasudevanpillai

Hydrophobically capped nanocrystals of formamidinium lead bromide (FAPbBr3) perovskite (PNC) show bright and stable fluorescence in solution and thin-film states. When compared with isolated PNCs in a solution, close-packed PNCs in a thin film show extended fluorescence lifetime (ca. 4.2 μs), which is due to hopping or migration of photogenerated excitons among PNCs. Both fluorescence quantum efficiency and lifetime decrease in a PNC thin film doped with fullerene (C60), which is attributed to channeling of exciton migration into electron transfer to C60. On the other hand, quenching of fluorescence intensity of a PNC solution is not accompanied by any change in fluorescence lifetime, indicating static electron transfer to C60 adsorbed onto the hydrophobic surface of individual PNCs. Exciton migration among close-packed PNCs and electron transfer to C60 places C60-doped PNC thin films among cost-effective antenna systems for solar cells.

EXCITON theory; CHARGE exchange; BROMIDES; PEROVSKITE synthesis; NANOCRYSTALS; FULLERENES

Angewandte Chemie International Edition, 2017, Vol 56, Issue 5, p1214

1433-7851

Academic Journal

10.1002/anie.201610070