Hybrid photoelectrochemical and photovoltaic cells for simultaneous production of chemical fuels and electrical power


Harnessing solar energy to drive photoelectrochemical reactions is widely studied for sustainable fuel production and versatile energy storage over different timescales. However, the majority of solar photoelectrochemical cells cannot drive the overall photosynthesis reactions without the assistance of an external power source. A device for simultaneous and direct production of renewable fuels and electrical power from sunlight is now proposed. This hybrid photoelectrochemical and photovoltaic device allows tunable control over the branching ratio between two high-value products of solar energy conversion, requires relatively simple modification to existing photovoltaic technologies, and circumvents the photocurrent mismatches that lead to significant loss in tandem photoelectrochemical systems comprising chemically stable photoelectrodes. Our proof-of-concept device is based on a transition metal oxide photoanode monolithically integrated onto silicon that possesses both front- and backside photovoltaic junctions. This integrated assembly drives spontaneous overall water splitting with no external power source, while also producing electricity near the maximum power point of the backside photovoltaic junction. The concept that photogenerated charge carriers can be controllably directed to produce electricity and chemical fuel provides an opportunity to significantly increase the energy return on energy invested in solar fuels systems and can be adapted to a variety of architectures assembled from different materials.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Fig. 1: Current mismatch losses and the HPEV cell.
Fig. 2: Simulated HPEV performance.
Fig. 3: HPEV cell characterization.
Fig. 4: Equivalent circuit analysis of HPEV cells.

Data availability

The data that support the findings within this paper are available from the corresponding author upon request.


  1. 1.

    Bak, T., Nowotny, J., Rekas, M. & Sorrell, C. C. Photo-electrochemical hydrogen generation from water using solar energy. Materials-related aspects. Int. J. Hydrogen Energy 27, 991–1022 (2002).

    CAS  Article  Google Scholar 

  2. 2.

    Walter, M. G. et al. Solar water splitting cells. Chem. Rev. 110, 6446–6473 (2010).

    CAS  Article  Google Scholar 

  3. 3.

    Hu, S., Xiang, C., Haussener, S., Berger, A. D. & Lewis, N. S. An analysis of the optimal band gaps of light absorbers in integrated tandem photoelectrochemical water-splitting systems. Energy Environ. Sci. 6, 2984–2993 (2013).

    CAS  Article  Google Scholar 

  4. 4.

    Liu, C., Tang, J., Chen, H. M., Liu, B. & Yang, P. A fully integrated nanosystem of semiconductor nanowires for direct solar water splitting. Nano Lett. 13, 2989–2992 (2013).

    CAS  Article  Google Scholar 

  5. 5.

    Shaner, M. R. et al. Photoelectrochemistry of core–shell tandem junction n–p+-Si/n-WO3 microwire array photoelectrodes. Energy Environ. Sci. 7, 779–790 (2014).

    CAS  Article  Google Scholar 

  6. 6.

    Chakthranont, P., Hellstern, T. R., McEnaney, J. M. & Jaramillo, T. F. Design and fabrication of a precious metal-free tandem core-shell p +n Si/W-doped BiVO4 photoanode for unassisted water splitting. Adv. Energy Mater. 7, 1701515 (2017).

    Article  Google Scholar 

  7. 7.

    Jang, J.-W. et al. Enabling unassisted solar water splitting by iron oxide and silicon. Nat. Commun. 6, 7447 (2015).

    Article  Google Scholar 

  8. 8.

    Abdi, F. F. et al. Efficient solar water splitting by enhanced charge separation in a bismuth vanadate–silicon tandem photoelectrode. Nat. Commun. 4, 2195 (2013).

    Article  Google Scholar 

  9. 9.

    Sheridan, M. V. et al. All-in-one derivatized tandem p+n-silicon-SnO2/TiO2 water splitting photoelectrochemical cell. Nano Lett. 17, 2440–2446 (2017).

    CAS  Article  Google Scholar 

  10. 10.

    Shaner, M. R., McDowell, M. T., Pien, A., Atwater, H. A. & Lewis, N. S. Si/TiO2 tandem-junction microwire arrays for unassisted solar-driven water splitting. J. Electrochem. Soc. 163, H261–H264 (2016).

    CAS  Article  Google Scholar 

  11. 11.

    Sivula, K., Le Formal, F. & Grätzel, M. Solar water splitting: progress using hematite (α-Fe2O3) photoelectrodes. ChemSusChem 4, 432–449 (2011).

    CAS  Article  Google Scholar 

  12. 12.

    Warren, S. C. et al. Identifying champion nanostructures for solar water-splitting. Nat. Mater. 12, 842–849 (2013).

    CAS  Article  Google Scholar 

  13. 13.

    Tilley, S. D., Cornuz, M., Sivula, K. & Grätzel, M. Light-induced water splitting with hematite: improved nanostructure and iridium oxide catalysis. Angew. Chem. Int. Ed. 49, 6405–6408 (2010).

    CAS  Article  Google Scholar 

  14. 14.

    Dotan, H. et al. Resonant light trapping in ultrathin films for water splitting. Nat. Mater. 12, 158–164 (2013).

    CAS  Article  Google Scholar 

  15. 15.

    Liu, G. et al. Enabling an integrated tantalum nitride photoanode to approach the theoretical photocurrent limit for solar water splitting. Energy Environ. Sci. 9, 1327–1334 (2016).

    CAS  Article  Google Scholar 

  16. 16.

    Takata, T. et al. Visible-light-driven photocatalytic behavior of tantalum-oxynitride and nitride. Res. Chem. Intermed. 33, 13–25 (2007).

    CAS  Article  Google Scholar 

  17. 17.

    Li, Y. et al. Vertically aligned Ta3N5 nanorod arrays for solar-driven photoelectrochemical water splitting. Adv. Mater. 25, 125–131 (2013).

    CAS  Article  Google Scholar 

  18. 18.

    Zhong, M. et al. Highly active GaN-stabilized Ta3 N5 thin-film photoanode for solar water oxidation. Angew. Chem. Int. Ed. 56, 4739–4743 (2017).

    CAS  Article  Google Scholar 

  19. 19.

    Rothschild, A. & Dotan, H. Beating the efficiency of photovoltaics-powered electrolysis with tandem cell photoelectrolysis. ACS Energy Lett. 2, 45–51 (2016).

    Article  Google Scholar 

  20. 20.

    Pihosh, Y. et al. Photocatalytic generation of hydrogen by core-shell WO3/BiVO4 nanorods with ultimate water splitting efficiency. Sci. Rep. 5, 11141 (2015).

    Article  Google Scholar 

  21. 21.

    Zhao, J., Wang, A. & Green, Ma 24.5% efficiency silicon PERT cells on tmMCZ substrates and 24.7% efficiency PERL cells on FZ substrates. Prog. Photovoltaics Res. Appl. 7, 471–474 (1999).

    CAS  Article  Google Scholar 

  22. 22.

    Mulligan, W. P. et al. in Proceedings of the 19th EPVSEC 3–6 (2004).

  23. 23.

    Segev, G. et al. The spatial collection efficiency of charge carriers in photovoltaic and photoelectrochemical cells. Joule 2, 210–224 (2018).

    CAS  Article  Google Scholar 

  24. 24.

    Coridan, R. H. et al. Methods for comparing the performance of energy-conversion systems for use in solar fuels and solar electricity generation. Energy Environ. Sci. 8, 2886–2901 (2015).

    CAS  Article  Google Scholar 

  25. 25.

    Döscher, H., Geisz, J. F., Deutsch, T. G. & Turner, J. A. Sunlight absorption in water—efficiency and design implications for photoelectrochemical devices. Energy Environ. Sci. 7, 2951–2956 (2014).

    Article  Google Scholar 

  26. 26.

    Bolton, J. R., Strickler, S. J. & Connolly, J. S. Limiting and realizable efficiencies of solar photolysis of water. Nature 316, 495–500 (1985).

    CAS  Article  Google Scholar 

Download references


This material is based on work performed by the Joint Center for Artificial Photosynthesis, a DOE Energy Innovation Hub, supported through the Office of Science of the US Department of Energy under award no. DE-SC0004993. G.S. acknowledges support by the Israeli Ministry of National Infrastructure, Energy and Water Resources under the programme for post-doctoral fellowships.

Author information




G.S. and I.D.S. initiated this research. G.S. and J.W.B. fabricated the devices. G.S. carried out the measurements and simulations. J.B.G. conducted the EROEI analysis and wrote the section about it. G.S. and I.D.S. wrote the rest of the manuscript. All authors commented on the manuscript. I.D.S. directed the research.

Corresponding author

Correspondence to Ian D. Sharp.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Publisher’s note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary information

Supplementary Information

Supplementary Figures 1–17, Supplementary Tables 1–3, Supplementary References 1–21

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Segev, G., Beeman, J.W., Greenblatt, J.B. et al. Hybrid photoelectrochemical and photovoltaic cells for simultaneous production of chemical fuels and electrical power. Nature Mater 17, 1115–1121 (2018). https://doi.org/10.1038/s41563-018-0198-y

Download citation

Further reading


Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

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