Spiro-OMeTAD single crystals: Remarkably enhanced charge-carrier transport via mesoscale ordering
KAUST DepartmentPhysical Sciences and Engineering (PSE) Division
KAUST Solar Center (KSC)
KAUST Catalysis Center (KCC)
Imaging and Characterization Core Lab
MetadataShow full item record
AbstractWe report the crystal structure and hole-transport mechanism in spiro-OMeTAD [2,2′,7,7′-tetrakis(N,N-di-p-methoxyphenyl-amine)9,9′-spirobifluorene], the dominant hole-transporting material in perovskite and solid-state dye-sensitized solar cells. Despite spiro-OMeTAD’s paramount role in such devices, its crystal structure was unknown because of highly disordered solution-processed films; the hole-transport pathways remained ill-defined and the charge carrier mobilities were low, posing a major bottleneck for advancing cell efficiencies. We devised an antisolvent crystallization strategy to grow single crystals of spiro-OMeTAD, which allowed us to experimentally elucidate its molecular packing and transport properties. Electronic structure calculations enabled us to map spiro-OMeTAD’s intermolecular charge-hopping pathways. Promisingly, single-crystal mobilities were found to exceed their thin-film counterparts by three orders of magnitude. Our findings underscore mesoscale ordering as a key strategy to achieving breakthroughs in hole-transport material engineering of solar cells.
CitationSpiro-OMeTAD single crystals: Remarkably enhanced charge-carrier transport via mesoscale ordering 2016, 2 (4):e1501491 Science Advances
SponsorsO.M.B. and J.-L.B acknowledges the financial support of King Abdullah University of Science and Technology Grant URF/1/2268-01-01. J.-L.B. also acknowledges support from ONR Global through Grant N62909-15-1-2003. H.D. thanks the National Natural Science Foundation of China (91433115). Author contributions: D.S. conceived the idea. O.M.B. crafted the overall experimental plan and directed the research. D.S. optimized the crystallization. D.S. and W.X. performed the confocal optical microscope imaging. D.S. and Y.H. performed single-crystal XRD and data analysis. D.S., X.Q., H.D., T.L., and W.H. planned and performed the mobility measurements and analyzed the data. Y.L., C.Z., and J.-L.B. planned and performed the theoretical calculations. Y.L., C.Z., and J.-L.B. analyzed the data of the theoretical part. J.P. assisted D.S. in the experiments. D.S., Y.L., J.-L.B., and O.M.B. wrote the manuscript. All authors discussed and commented on the manuscript. Competing interests: The authors declare that they have no competing interests. Data and materials availability: All data needed to evaluate the conclusions in the paper are present in the paper and/or the Supplementary Materials. Additional data related to this paper may be requested from the authors.
Is Supplemented ByShi, D., Qin, X., Li, Y., He, Y., Zhong, C., Pan, J., … Bakr, O. M. (2016). CCDC 1475944: Experimental Crystal Structure Determination [Data set]. Cambridge Crystallographic Data Centre. https://doi.org/10.5517/ccdc.csd.cc1ljv32
- Hierarchically Structured Hole Transport Layers of Spiro-OMeTAD and Multiwalled Carbon Nanotubes for Perovskite Solar Cells.
- Authors: Lee J, Menamparambath MM, Hwang JY, Baik S
- Issue date: 2015 Jul 20
- Benzoyl Peroxide as an Efficient Dopant for Spiro-OMeTAD in Perovskite Solar Cells.
- Authors: Liu Q, Fan L, Zhang Q, Zhou A, Wang B, Bai H, Tian Q, Fan B, Zhang T
- Issue date: 2017 Aug 10
- Perovskite Solar Cells: Influence of Hole Transporting Materials on Power Conversion Efficiency.
- Authors: Ameen S, Rub MA, Kosa SA, Alamry KA, Akhtar MS, Shin HS, Seo HK, Asiri AM, Nazeeruddin MK
- Issue date: 2016 Jan 8
- Low-Cost Carbazole-Based Hole-Transport Material for Highly Efficient Perovskite Solar Cells.
- Authors: Chen Z, Li H, Zheng X, Zhang Q, Li Z, Hao Y, Fang G
- Issue date: 2017 Aug 10
- Hole-transporting small molecules based on thiophene cores for high efficiency perovskite solar cells.
- Authors: Li H, Fu K, Boix PP, Wong LH, Hagfeldt A, Grätzel M, Mhaisalkar SG, Grimsdale AC
- Issue date: 2014 Dec