Printed assemblies of GaAs photoelectrodes with decoupled optical and reactive interfaces for unassisted solar water splitting


Despite their excellent photophysical properties and record-high solar-to-hydrogen conversion efficiency, the high cost and limited stability of III–V compound semiconductors prohibit their practical application in solar-driven photoelectrochemical water splitting. Here we present a strategy for III–V photocatalysis that can circumvent these difficulties via printed assemblies of epitaxially grown compound semiconductors. A thin film stack of GaAs-based epitaxial materials is released from the growth wafer and printed onto a non-native transparent substrate to form an integrated photocatalytic electrode for solar hydrogen generation. The heterogeneously integrated electrode configuration together with specialized epitaxial design serve to decouple the material interfaces for illumination and electrocatalysis. Subsequently, this allows independent control and optimization of light absorption, carrier transport, charge transfer, and material stability. Using this approach, we construct a series-connected wireless tandem system of GaAs photoelectrodes and demonstrate 13.1% solar-to-hydrogen conversion efficiency of unassisted-mode water splitting.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Figure 1: Fabrication of integrated bifacial GaAs photoelectrodes.
Figure 2: Photovoltaic and optical properties of epitaxial GaAs photocathodes on wafer and after transfer printing.
Figure 3: Photoelectrochemical performance of integrated bifacial GaAs photocathodes in the HER.
Figure 4: Stability of integrated bifacial GaAs photocathodes.
Figure 5: Unassisted solar water splitting with a tandem electrode system of bifacial GaAs photoelectrodes.


  1. 1

    Powell, D. M. et al. Crystalline silicon photovoltaics: a cost analysis framework for determining technology pathways to reach baseload electricity costs. Energy Environ. Sci. 5, 5874–5883 (2012).

  2. 2

    Kang, M. H. & Rohatgi, A. Quantitative analysis of the levelized cost of electricity of commercial scale photovoltaics systems in the US. Sol. Energy Mater. Sol. Cells 154, 71–77 (2016).

  3. 3

    Cook, T. R. et al. Solar energy supply and storage for the legacy and nonlegacy worlds. Chem. Rev. 110, 6474–6502 (2010).

  4. 4

    Lewis, N. S. & Nocera, D. G. Powering the planet: chemical challenges in solar energy utilization. Proc. Natl Acad. Sci. USA 103, 15729–15735 (2006).

  5. 5

    Fujishima, A. & Honda, K. Electrochemical photolysis of water at a semiconductor electrode. Nature 238, 37–38 (1972).

  6. 6

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

  7. 7

    Lin, F. D. & Boettcher, S. W. Adaptive semiconductor/electrocatalyst junctions in water-splitting photoanodes. Nat. Mater. 13, 81–86 (2014).

  8. 8

    Kim, D., Sakimoto, K. K., Hong, D. C. & Yang, P. D. Artificial photosynthesis for sustainable fuel and chemical production. Angew Chem. Int. Ed. 54, 3259–3266 (2015).

  9. 9

    Lee, M. H. et al. p-Type InP nanopillar photocathodes for efficient solar-driven hydrogen production. Angew Chem. Int. Ed. 51, 10760–10764 (2012).

  10. 10

    Gu, J. et al. Water reduction by a p-GaInP2 photoelectrode stabilized by an amorphous TiO2 coating and a molecular cobalt catalyst. Nat. Mater. 15, 456–460 (2016).

  11. 11

    Khaselev, O. & Turner, J. A. A monolithic photovoltaic-photoelectrochemical device for hydrogen production via water splitting. Science 280, 425–427 (1998).

  12. 12

    Verlage, E. et al. A monolithically integrated, intrinsically safe, 10% efficient, solar-driven water-splitting system based on active, stable earth-abundant electrocatalysts in conjunction with tandem III–V light absorbers protected by amorphous TiO2 films. Energy Environ. Sci. 8, 3166–3172 (2015).

  13. 13

    Pinaud, B. A. et al. Technical and economic feasibility of centralized facilities for solar hydrogen production via photocatalysis and photoelectrochemistry. Energy Environ. Sci. 6, 1983–2002 (2013).

  14. 14

    Dumortier, M. & Haussener, S. Design guidelines for concentrated photo-electrochemical water splitting devices based on energy and greenhouse gas yield ratios. Energy Environ. Sci. 8, 3069–3082 (2015).

  15. 15

    Woodhouse, M. & Goodrich, A. A Manufacturing Cost Analysis Relevant to Single- and Dual-Junction Photovoltaic Cells Fabricated with III–Vs and III–Vs Grown on Czochralski Silicon NREL Report PR-6A20-60126, 92 (NREL, 2014).

  16. 16

    Erne, B. H., Stchakovsky, M., Ozanam, F. & Chazalviel, J. N. Surface composition of n-GaAs cathodes during hydrogen evolution characterized by in situ ultraviolet-visible ellipsometry and in situ infrared spectroscopy. J. Electrochem. Soc. 145, 447–456 (1998).

  17. 17

    Ostermayer, F. W. & Kohl, P. A. Photoelectrochemical etching of p-GaAs. Appl. Phys. Lett. 39, 76–78 (1981).

  18. 18

    Hu, S. et al. Amorphous TiO2 coatings stabilize Si, GaAs, and GaP photoanodes for efficient water oxidation. Science 344, 1005–1009 (2014).

  19. 19

    Scheuermann, A. G. et al. Design principles for maximizing photovoltage in metal-oxide-protected water-splitting photoanodes. Nat. Mater. 15, 99–105 (2016).

  20. 20

    Chen, Y. W. et al. Atomic layer-deposited tunnel oxide stabilizes silicon photoanodes for water oxidation. Nat. Mater. 10, 539–544 (2011).

  21. 21

    Kenney, M. J. et al. High-performance silicon photoanodes passivated with ultrathin nickel films for water oxidation. Science 342, 836–840 (2013).

  22. 22

    Ji, L. et al. A silicon-based photocathode for water reduction with an epitaxial SrTiO3 protection layer and a nanostructured catalyst. Nat. Nanotech. 10, 84–90 (2015).

  23. 23

    Sun, K. et al. Nickel oxide functionalized silicon for efficient photo-oxidation of water. Energy Environ. Sci. 5, 7872–7877 (2012).

  24. 24

    Fan, F. R. F., Keil, R. G. & Bard, A. J. Semiconductor electrodes. 48. Photo-oxidation of halides and water on N-silicon protected with silicide layers. J. Am. Chem. Soc. 105, 220–224 (1983).

  25. 25

    Lin, Y. et al. Amorphous Si thin film based photocathodes with high photovoltage for efficient hydrogen production. Nano Lett. 13, 5615–5618 (2013).

  26. 26

    Nielander, A. C., Shaner, M. R., Papadantonakis, K. M., Francis, S. A. & Lewis, N. S. A taxonomy for solar fuels generators. Energy Environ. Sci. 8, 16–25 (2015).

  27. 27

    Yablonovitch, E., Gmitter, T., Harbison, J. P. & Bhat, R. Extreme selectivity in the lift-off of epitaxial GaAs films. Appl. Phys. Lett. 51, 2222–2224 (1987).

  28. 28

    Yoon, J. et al. GaAs photovoltaics and optoelectronics using releasable multilayer epitaxial assemblies. Nature 465, 329–333 (2010).

  29. 29

    Cheng, C. W. et al. Epitaxial lift-off process for gallium arsenide substrate reuse and flexible electronics. Nat. Commun. 4, 1577 (2013).

  30. 30

    Kang, D., Lee, S. M., Kwong, A. & Yoon, J. Dramatically enhanced performance of flexible micro-VCSELs via thermally engineered heterogeneous composite assemblies. Adv. Opt. Mater. 3, 1072–1078 (2015).

  31. 31

    Yoon, J. et al. Flexible concentrator photovoltaics based on microscale silicon solar cells embedded in luminescent waveguides. Nat. Commun. 2, 343 (2011).

  32. 32

    Lee, S. M. et al. Printable nanostructured silicon solar cells for high-performance, large-area flexible photovoltaics. ACS Nano 8, 10507–10516 (2014).

  33. 33

    Lee, S. M. et al. High performance ultrathin GaAs solar cells enabled with heterogeneously integrated dielectric periodic nanostructures. ACS Nano 9, 10356–10365 (2015).

  34. 34

    Bhatt, M. D. & Lee, J. S. Recent theoretical progress in the development of photoanode materials for solar water splitting photoelectrochemical cells. J. Mater. Chem. A 3, 10632–10659 (2015).

  35. 35

    Shen, L. et al. Nanostructured silicon photocathodes for solar water splitting patterned by the self-assembly of lamellar block copolymers. ACS Appl. Mater. Interfaces 7, 26043–26049 (2015).

  36. 36

    Dimroth, F. et al. Wafer bonded four-junction GaInP/GaAs//GaInAsP/GaInAs concentrator solar cells with 44.7% efficiency. Prog. Photovolt. 22, 277–282 (2014).

  37. 37

    King, R. R. et al. 40% efficient metamorphic GaInP/GaInAs/Ge multijunction solar cells. Appl. Phys. Lett. 90, 183516 (2007).

  38. 38

    Park, S. M. & Barber, M. E. Thermodynamic stabilities of semiconductor electrodes. J. Electroanal. Chem. 99, 67–75 (1979).

  39. 39

    Hagio, M. Electrode-reaction of GaAs metal-semiconductor field-effect transistors in deionized water. J. Electrochem. Soc. 140, 2402–2405 (1993).

  40. 40

    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).

  41. 41

    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).

  42. 42

    Jacobsson, T. J., Fjallstrom, V., Sahlberg, M., Edoff, M. & Edvinsson, T. A monolithic device for solar water splitting based on series interconnected thin film absorbers reaching over 10% solar-to-hydrogen efficiency. Energy Environ. Sci. 6, 3676–3683 (2013).

  43. 43

    Zhao, Y. X., Hernandez-Pagan, E. A., Vargas-Barbosa, N. M., Dysart, J. L. & Mallouk, T. E. A high yield synthesis of ligand-free iridium oxide nanoparticles with high electrocatalytic activity. J. Phys. Chem. Lett. 2, 402–406 (2011).

  44. 44

    Zhao, Y. X., Vargas-Barbosa, N. M., Hernandez-Pagan, E. A. & Mallouk, T. E. Anodic deposition of colloidal iridium oxide thin films from hexahydroxyiridate(IV) solutions. Small 7, 2087–2093 (2011).

  45. 45

    Brown, D. E., Mahmood, M. N., Turner, A. K., Hall, S. M. & Fogarty, P. O. Low overvoltage electrocatalysts for hydrogen evolving electrodes. Int. J. Hydrog. Energy 7, 405–410 (1982).

  46. 46

    Landon, J. et al. Spectroscopic characterization of mixed Fe–Ni oxide electrocatalysts for the oxygen evolution reaction in alkaline electrolytes. ACS Catal. 2, 1793–1801 (2012).

  47. 47

    Kang, D. S. et al. Carbon-doped GaAs single junction solar microcells grown in multilayer epitaxial assemblies. Appl. Phys. Lett. 102, 253902, (2013).

  48. 48

    Osterwald, C. R. Translation of device performance-measurements to reference conditions. Sol. Cells 18, 269–279 (1986).

  49. 49

    Doscher, H., Young, J. L., Geisz, J. F., Turner, J. A. & Deutsch, T. G. Solar-to-hydrogen efficiency: shining light on photoelectrochemical device performance. Energy Environ. Sci. 9, 74–80 (2016).

Download references


D.K., H.L., H.C., Y.X., B.G. and J.Y. gratefully acknowledge National Science Foundation (ECCS-1202522, ECCS-1509897), USC startup fund, and Hanwha Advanced Materials Non-tenured faculty award. T.G.D., J.L.Y. and W.E.K. acknowledge support by the US Department of Energy (DOE), Office of Energy Efficiency & Renewable Energy, Fuel Cell Technologies Office under Contract No. DE-AC36-08GO28308 with the National Renewable Energy Laboratory. The authors thank D. Zhu and J. Curulli for help using facilities at Keck Photonics Laboratory and Center for Electron Microscope and MicroAnalysis (CEMMA) at USC, respectively.

Author information

J.Y. and D.K. conceived the idea and designed the experiment. D.K., J.L.Y., H.L., W.E.K., H.C., Y.X., B.G., T.G.D. and J.Y. performed the experiments. D.K., J.L.Y., H.L., W.E.K., H.C., T.G.D. and J.Y. analysed the data. D.K., J.L.Y., W.E.K., T.G.D. and J.Y. wrote the paper.

Correspondence to Jongseung Yoon.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary Information

Supplementary Methods, Supplementary Figures 1–14, Supplementary Tables 1–3. (PDF 1145 kb)

Supplementary Video 1

Unassisted solar water splitting with a wireless, tandem system of GaAs photoelectrodes. This video shows unassisted water splitting using two series-connected GaAs photoelectrodes in 0.5M H2SO4 aqueous solution under simulated AM1.5G solar illumination. While the light is turned on from the back side, oxygen and hydrogen gases are produced on the front side (the catalytic interface) of the photoanode (left) and the photocathode (right), respectively. (MP4 20060 kb)

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Kang, D., Young, J., Lim, H. et al. Printed assemblies of GaAs photoelectrodes with decoupled optical and reactive interfaces for unassisted solar water splitting. Nat Energy 2, 17043 (2017).

Download citation

Further reading