A Caltech Library Service

Monolithic Photoelectrochemical Device for 19% Direct Water Splitting

Cheng, Wen-Hui and Richter, Matthias H. and May, Matthias M. and Ohlmann, Jens and Lackner, David and Dimroth, Frank and Hannappel, Thomas and Atwater, Harry A. and Lewerenz, Hans-Joachim (2018) Monolithic Photoelectrochemical Device for 19% Direct Water Splitting. ACS Energy Letters, 3 (8). pp. 1795-1800. ISSN 2380-8195. doi:10.1021/acsenergylett.8b00920.

[img] PDF - Accepted Version
See Usage Policy.

[img] PDF - Submitted Version
See Usage Policy.

[img] PDF (Device fabrication; materials characterization techniques; TiO2 characterization; surface layer band alignment; absorption enhancement by TiO2; optimization of the optical design; assessment of the solar-to-hydrogen efficiency measurement; comparative...) - Supplemental Material
See Usage Policy.


Use this Persistent URL to link to this item:


Efficient unassisted solar water splitting, a pathway to storable renewable energy in the form of chemical bonds, requires optimization of a photoelectrochemical device based on photovoltaic tandem heterojunctions. We report a monolithic photocathode device architecture that exhibits significantly reduced surface reflectivity, minimizing parasitic light absorption and reflection losses. A tailored multifunctional crystalline titania interphase layer acts as a corrosion protection layer, with favorable band alignment between the semiconductor conduction band and the energy level for water reduction, facilitating electron transport at the cathode–electrolyte interface. It also provides a favorable substrate for adhesion of high-activity Rh catalyst nanoparticles. Under simulated AM 1.5G irradiation, solar-to-hydrogen efficiencies of 19.3 and 18.5% are obtained in acidic and neutral electrolytes, respectively. The system reaches a value of 0.85 of the theoretical limit for photoelectrochemical water splitting for the energy gap combination employed in the tandem-junction photoelectrode structure.

Item Type:Article
Related URLs:
URLURL TypeDescription Information Paper
Cheng, Wen-Hui0000-0003-3233-4606
Richter, Matthias H.0000-0003-0091-2045
May, Matthias M.0000-0002-1252-806X
Ohlmann, Jens0000-0003-3229-1482
Lackner, David0000-0001-8170-0874
Dimroth, Frank0000-0002-3615-4437
Hannappel, Thomas0000-0002-6307-9831
Atwater, Harry A.0000-0001-9435-0201
Lewerenz, Hans-Joachim0000-0001-8433-9471
Additional Information:© 2018 American Chemical Society. Received: June 2, 2018; Accepted: June 25, 2018; Published: June 25, 2018. The authors acknowledge Katherine T. Fountaine for the calculation of theoretical photocurrent efficiencies of 2J PEC devices. This work was supported through the Office of Science of the U.S. Department of Energy (DOE) under Award No. DE SC0004993 to the Joint Center for Artificial Photosynthesis, a DOE Energy Innovation Hub. Research was in part carried out at the Molecular Materials Research Center of the Beckman Institute of the California Institute of Technology. The work on tandem absorbers was funded by the German Federal Ministry of Education and research (BMBF) under Contract Number FKZ 03F0432A (HyCon). M.M.M. acknowledges funding from the fellowship programme of the German National Academy of Sciences Leopoldina, Grant LPDS 2015-09. Author Contributions: T.H., H.J.L, M.M.M., W.H.C., M.H.R. and H.A.A. conceived of the experimental study. W.H.C. and M.H.R. executed the experiments and did the data analysis. J.O., D.L., and F.D. prepared the tandem absorber. W.H.C., M.H.R., H.J.L., and H.A.A. wrote the paper, and all authors commented on the manuscript. The authors declare no competing financial interest.
Funding AgencyGrant Number
Department of Energy (DOE)DE-SC0004993
Bundesministerium für Bildung und Forschung (BMBF)FKZ 03F0432A
Deutsche Akademie der Naturforscher LeopoldinaLPDS 2015-09
Issue or Number:8
Record Number:CaltechAUTHORS:20170731-084813550
Persistent URL:
Official Citation:Monolithic Photoelectrochemical Device for Direct Water Splitting with 19% Efficiency Wen-Hui Cheng, Matthias H. Richter, Matthias M. May, Jens Ohlmann, David Lackner, Frank Dimroth, Thomas Hannappel, Harry A. Atwater, and Hans-Joachim Lewerenz ACS Energy Letters 2018 3 (8), 1795-1800 DOI: 10.1021/acsenergylett.8b00920
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:79579
Deposited By: Tony Diaz
Deposited On:01 Aug 2017 19:59
Last Modified:15 Nov 2021 17:49

Repository Staff Only: item control page