Department of Physics
Polyfluorene derivatives arehHigh-performance organic hole-transporting materials for inorganic−organic hybrid perovskite solar cells
© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Photovoltaics based on organic-inorganic perovskites offer new promise to address the contemporary energy and environmental issues. These solar cells have so far largely relied on small-molecule hole transport materials such as spiro-OMeTAD, which commonly suffer from high cost and low mobility. In principle, polyfl uorene copolymers can be an ideal alternative to spiro- OMeTAD, given their low price, high hole mobility and good processability, but this potential has not been explored. Herein, polyfl uorene derived polymers- TFB and PFB, which contain fl uorine and arylamine groups, are demonstrated and can indeed rival or even outperform spiro-OMeTAD as efficient holeconducting materials for perovskite solar cells. In particular, under the one-step perovskite deposition condition, TFB achieves a 10.92% power conversion efficiency that is considerably higher than that with spiro-OMeTAD (9.78%), while using the two-step perovskite deposition method, about 13% efficient solar cells with TFB (12.80%) and spiro-OMeTAD (13.58%) are delivered. Photoluminescence reveals the efficient hole extraction and diffusion at the interface between CH 3 NH 3 PbI 3 and the hole conducting polymer. Impedance spectroscopy uncovers the higher electrical conductivity and lower series resistance than spiro-OMeTAD, accounting for the signifi cantly higher fi ll factor, photocurrent and open-circuit voltage of the TFB-derived cells than with spiro-MeOTAD.
Source Publication Title
Advanced Functional Materials
Link to Publisher's Edition
Zhu, Z., Bai, Y., Lee, H., Mu, C., Zhang, T., Zhang, L., Wang, J., Yan, H., So, S., & Yang, S. (2014). Polyfluorene derivatives arehHigh-performance organic hole-transporting materials for inorganic−organic hybrid perovskite solar cells. Advanced Functional Materials, 24 (46), 7357-7365. https://doi.org/10.1002/adfm.201401557