Mesoporous TiO2 single crystals delivering enhanced mobility and optoelectronic device performance

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Abstract

Mesoporous ceramics and semiconductors enable low-cost solar power, solar fuel, (photo)catalyst and electrical energy storage technologies1. State-of-the-art, printable high-surface-area electrodes are fabricated from thermally sintered pre-formed nanocrystals2,3,4,5. Mesoporosity provides the desired highly accessible surfaces but many applications also demand long-range electronic connectivity and structural coherence6. A mesoporous single-crystal (MSC) semiconductor can meet both criteria. Here we demonstrate a general synthetic method of growing semiconductor MSCs of anatase TiO2 based on seeded nucleation and growth inside a mesoporous template immersed in a dilute reaction solution. We show that both isolated MSCs and ensembles incorporated into films have substantially higher conductivities and electron mobilities than does nanocrystalline TiO2. Conventional nanocrystals, unlike MSCs, require in-film thermal sintering to reinforce electronic contact between particles, thus increasing fabrication cost, limiting the use of flexible substrates and precluding, for instance, multijunction solar cell processing. Using MSC films processed entirely below 150 °C, we have fabricated all-solid-state, low-temperature sensitized solar cells that have 7.3 per cent efficiency, the highest efficiency yet reported. These high-surface-area anatase single crystals will find application in many different technologies, and this generic synthetic strategy extends the possibility of mesoporous single-crystal growth to a range of functional ceramics and semiconductors.

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Figure 1: MSC synthesis of TiO2.
Figure 2: X-ray and electron diffraction of mesoporous TiO 2 crystals.
Figure 3: MSC size control via nucleation seed density.
Figure 4: Electronic properties and device performance of MSCs.

References

  1. 1

    Weickert, J., Dunbar, R. B., Hesse, H. C., Wiedemann, W. & Schmidt-Mende, L. Nanostructured organic and hybrid solar cells. Adv. Mater. 23, 1810–1828 (2011)

    CAS  Article  Google Scholar 

  2. 2

    Yella, A. et al. Porphyrin-sensitized solar cells with cobalt (ii/iii) based redox electrolyte exceed 12 percent efficiency. Science 334, 629–634 (2011)

    CAS  ADS  Article  Google Scholar 

  3. 3

    O'Regan, B. & Grätzel, M. A low-cost, high-efficiency solar cell based on dye-sensitized colloidal TiO2 . Nature 353, 737–740 (1991)

    CAS  ADS  Article  Google Scholar 

  4. 4

    Grätzel, M. Photoelectrochemical cells. Nature 414, 338–344 (2001)

    ADS  Article  Google Scholar 

  5. 5

    Lee, M. M., Teuscher, J., Miyasaka, T., Murakami, T. N. & Snaith, H. J. Efficient hybrid solar cells based on meso-superstructured organometal halide perovskites. Science 338, 643–647 (2012)

    CAS  ADS  Article  Google Scholar 

  6. 6

    Docampo, P., Guldin, S., Steiner, U. & Snaith, H. J. Charge transport limitations in self-assembled TiO2 photoanodes for solid-state dye-sensitized solar cells. J. Phys. Chem. Lett.. http://dx.doi.org/10.1021/jz400084n (in the press)

  7. 7

    Schüth, F. Endo- and exotemplating to create high-surface-area inorganic materials. Angew. Chem. Int. Edn 42, 3604–3622 (2003)

    Article  Google Scholar 

  8. 8

    Lu, A.-H. & Schüth, F. Nanocasting: a versatile strategy for creating nanostructured porous materials. Adv. Mater. 18, 1793–1805 (2006)

    CAS  Article  Google Scholar 

  9. 9

    Dickinson, C. et al. Formation mechanism of porous single-crystal Cr2O3 and Co3O4 templated by mesoporous silica. Chem. Mater. 18, 3088–3095 (2006)

    CAS  Article  Google Scholar 

  10. 10

    Tian, B. et al. General synthesis of ordered crystallized metal oxide nanoarrays replicated by microwave-digested mesoporous silica. Adv. Mater. 15, 1370–1374 (2003)

    CAS  Article  Google Scholar 

  11. 11

    Yue, W. & Zhou, W. Synthesis of porous single crystals of metal oxides via a solid–liquid route. Chem. Mater. 19, 2359–2363 (2007)

    CAS  Article  Google Scholar 

  12. 12

    Yang, P., Zhao, D., Margolese, D. I., Chmelka, B. F. & Stucky, G. D. Generalised synthesis of large-pore mesoporous metal oxides with semicrystalline frameworks. Nature 396, 152–155 (1998)

    CAS  ADS  Article  Google Scholar 

  13. 13

    Li, D., Zhou, H. & Honma, I. Design and synthesis of self-ordered mesoporous nanocomposite through controlled in-situ crystallization. Nature Mater. 3, 65–72 (2004)

    CAS  ADS  Article  Google Scholar 

  14. 14

    Yu, J. C., Wang, X. & Fu, X. Pore-wall chemistry and photocatalytic activity of mesoporous titania molecular sieve films. Chem. Mater. 16, 1523–1530 (2004)

    CAS  Article  Google Scholar 

  15. 15

    Kondo, J. N. & Domen, K. Crystallization of mesoporous metal oxides. Chem. Mater. 20, 835–847 (2008)

    CAS  ADS  Article  Google Scholar 

  16. 16

    Yue, W. & Zhou, W. Crystalline mesoporous metal oxide. Prog. Nat. Sci. 18, 1329–1338 (2008)

    CAS  Article  Google Scholar 

  17. 17

    Jiao, K. et al. Growth of porous single-crystal Cr2O3 in a 3D mesopore system. Chem. Commun. 5618–5620 (2005)

  18. 18

    Arora, H. et al. Block copolymer self-assembly-directed single-crystal homo- and heteroepitaxial nanostructures. Science 330, 214–219 (2010)

    CAS  ADS  Article  Google Scholar 

  19. 19

    Yue, W. et al. Mesoporous monocrystalline TiO2 and its solid-state electrochemical properties. Chem. Mater. 21, 2540–2546 (2009)

    CAS  Article  Google Scholar 

  20. 20

    Bian, Z. et al. Single-crystal-like titania mesocages. Angew. Chem. Int. Edn 50, 1105–1108 (2011)

    CAS  Article  Google Scholar 

  21. 21

    Finnemore, A. S. et al. Nanostructured calcite single crystals with gyroid morphologies. Adv. Mater. 21, 3928–3932 (2009)

    CAS  Article  Google Scholar 

  22. 22

    Crossland, E. J. W. et al. A bicontinuous double gyroid dye-sensitized solar cell. Nano Lett. 9, 2807–2812 (2009)

    CAS  ADS  Article  Google Scholar 

  23. 23

    Yang, H. G. et al. Anatase TiO2 single crystals with a large percentage of reactive facets. Nature 453, 638–641 (2008)

    CAS  ADS  Article  Google Scholar 

  24. 24

    Zhang, D., Li, G., Yang, X. & Yu, J. C. A micrometer-size TiO2 single-crystal photocatalyst with remarkable 80% level of reactive facets. Chem. Commun. 4381–4383 (2009)

  25. 25

    Liu, G., Yu, J. C., Lu, G. Q. M. & Cheng, H.-M. Crystal facet engineering of semiconductor photocatalysts: motivations, advances and unique properties. Chem. Commun. 47, 6763–6783 (2011)

    CAS  Article  Google Scholar 

  26. 26

    Nakade, S. et al. Dependence of TiO2 nanoparticle preparation methods and annealing temperature on the efficiency of dye-sensitized solar cells. J. Phys. Chem. B 106, 10004–10010 (2002)

    CAS  Article  Google Scholar 

  27. 27

    Jiang, C. Y. et al. Low temperature processing solid-state dye sensitized solar cells. Appl. Phys. Lett. 100, 113901 (2012)

    ADS  Article  Google Scholar 

  28. 28

    Schmidt-Mende, L. et al. Organic dye for highly efficient solid-state dye-sensitized solar cells. Adv. Mater. 17, 813–815 (2005)

    CAS  Article  Google Scholar 

  29. 29

    Bogush, G. H., Tracy, M. A. & Zukoski, C. Z. IV Preparation of monodisperse silica particles: control of size and mass fraction. J. Non-Cryst. Solids 104, 95–106 (1988)

    CAS  ADS  Article  Google Scholar 

  30. 30

    Docampo, P. et al. Control of solid-state dye-sensitized solar cell performance by block-copolymer-directed TiO2 synthesis. Adv. Funct. Mater. 20, 1787–1796 (2010)

    CAS  Article  Google Scholar 

  31. 31

    Zakeeruddin, S. M. et al. Design, synthesis, and application of amphiphilic ruthenium polypyridyl photosensitizers in solar cells based on nanocrystalline TiO2 films. Langmuir 18, 952–954 (2002)

    CAS  Article  Google Scholar 

Download references

Acknowledgements

This work was funded by the European Community’s Seventh Framework Programme (FP7/2007-2013) under grant agreement number 246124 of the SANS project, the European Research Council (HYPER project number 279881), the Rhodes Trust, the Engineering and Physical Sciences Research Council, and the Government of the Republic of Trinidad and Tobago. We thank C. Ducati for help with indexing of electron diffraction patterns.

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E.J.W.C. and H.J.S. conceived the idea of the project. E.J.W.C. devised and performed materials synthesis and characterization. N.N. and V.S. fabricated and characterized solar cells and optoelectronic devices. T.L. and J.A.A.-W. contributed to electronic mobility measurements. E.J.W.C., H.J.S. and V.S. wrote the manuscript. All authors commented on the manuscript. H.J.S. supervised the project.

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Correspondence to Henry J. Snaith.

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The authors declare no competing financial interests.

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Crossland, E., Noel, N., Sivaram, V. et al. Mesoporous TiO2 single crystals delivering enhanced mobility and optoelectronic device performance. Nature 495, 215–219 (2013). https://doi.org/10.1038/nature11936

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