Subjects: Electronics and Communication Technology >> Other Disciplines of Electronics and Communication Technology submitted time 2022-10-21 Cooperative journals: 《桂林电子科技大学学报》
Abstract: To enhance the device-performance and long-term stability of printable mesoscopic perovskite solar cells (MPSCs),
an anion-cation synergistic strategy is proposed to introduce the ionic liquid additive 1-ethyl-3-methylimidazolium acetate
(EMIMAC) into the perovskite active layer and use it for the preparation of efficient and stable MPSCs. The experimental
results indicate that the imidazole (EMIM+ ) cation enables ionic defect passivation (e.g., Pb2+ and PbI3- ) through
the coordination effect, which is believed to be beneficial for perovskite crystallization. On the other hand, the acetate
(AC- ) anion tends to coordinate with TiO2 to passivate the oxygen vacancy defects on the TiO2 surface for improved interfacial
contact at the TiO2/perovskite interface. As a result, the synergistic effects of the EMIM+ cation and AC- anion in
the EMIMAC achieves better perovskite crystallinity, more efficient charge transport, and lower nonradiative recombination.
The power conversion efficiency (PCE) of the MPSCs increased from 13.83% to 15.48%, accompanied by a negligible
hysteresis. Furthermore, the unencapsulated MPSCs exhibited excellent long-term stability by maintaining 90% of the initial
PCE after exposure in air (RH=50±5%) for 60 days. The experimental results indicate that the ionic liquid additive
EMIMAC can effectively enhance the PCE and stability of the device, providing an effective strategy for further improving
the device-performance.