Letter | Published:

Mesoporous TiO2 single crystals delivering enhanced mobility and optoelectronic device performance

Nature volume 495, pages 215219 (14 March 2013) | Download Citation



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.

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.


  1. 1.

    , , , & Nanostructured organic and hybrid solar cells. Adv. Mater. 23, 1810–1828 (2011)

  2. 2.

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

  3. 3.

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

  4. 4.

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

  5. 5.

    , , , & Efficient hybrid solar cells based on meso-superstructured organometal halide perovskites. Science 338, 643–647 (2012)

  6. 6.

    , , & Charge transport limitations in self-assembled TiO2 photoanodes for solid-state dye-sensitized solar cells. J. Phys. Chem. Lett.. (in the press)

  7. 7.

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

  8. 8.

    & Nanocasting: a versatile strategy for creating nanostructured porous materials. Adv. Mater. 18, 1793–1805 (2006)

  9. 9.

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

  10. 10.

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

  11. 11.

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

  12. 12.

    , , , & Generalised synthesis of large-pore mesoporous metal oxides with semicrystalline frameworks. Nature 396, 152–155 (1998)

  13. 13.

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

  14. 14.

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

  15. 15.

    & Crystallization of mesoporous metal oxides. Chem. Mater. 20, 835–847 (2008)

  16. 16.

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

  17. 17.

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

  18. 18.

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

  19. 19.

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

  20. 20.

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

  21. 21.

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

  22. 22.

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

  23. 23.

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

  24. 24.

    , , & A micrometer-size TiO2 single-crystal photocatalyst with remarkable 80% level of reactive facets. Chem. Commun. 4381–4383 (2009)

  25. 25.

    , , & Crystal facet engineering of semiconductor photocatalysts: motivations, advances and unique properties. Chem. Commun. 47, 6763–6783 (2011)

  26. 26.

    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)

  27. 27.

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

  28. 28.

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

  29. 29.

    , & IV Preparation of monodisperse silica particles: control of size and mass fraction. J. Non-Cryst. Solids 104, 95–106 (1988)

  30. 30.

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

  31. 31.

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

Download references


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.

Author information


  1. Clarendon Laboratory, University of Oxford Parks Road, Oxford, OX1 3PU, UK

    • Edward J. W. Crossland
    • , Nakita Noel
    • , Varun Sivaram
    • , Tomas Leijtens
    • , Jack A. Alexander-Webber
    •  & Henry J. Snaith


  1. Search for Edward J. W. Crossland in:

  2. Search for Nakita Noel in:

  3. Search for Varun Sivaram in:

  4. Search for Tomas Leijtens in:

  5. Search for Jack A. Alexander-Webber in:

  6. Search for Henry J. Snaith in:


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.

Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to Henry J. Snaith.

Supplementary information

PDF files

  1. 1.

    Supplementary Information

    This file contains Supplementary Figures 1-4.

About this article

Publication history






Further reading


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.

Newsletter Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing