Recently, significant progress in the development of III–V/Si dual-junction solar cells has been achieved. This not only boosts the efficiency of Si-based photovoltaic solar cells but also offers the possibility of highly efficient green hydrogen production via solar water splitting. Using such dual-junction cells in a highly integrated photoelectrochemical approach and aiming for upscaled devices with solar-to-hydrogen (STH) efficiencies beyond 20%, however, the following frequently neglected contrary effects become relevant: (i) light absorption in the electrolyte layer in front of the top absorber and (ii) the impact of this layer on the Ohmic and transport losses. Here, we initially model the influence of the electrolyte layer thickness on the maximum achievable solar-to-hydrogen efficiency of a device with an Si bottom cell and show how the top absorber bandgap has to be adapted to minimize efficiency losses. Then, the contrary effects of increasing Ohmic and transport losses with the decreasing electrolyte layer thickness are evaluated. This allows us to estimate an optimum electrolyte layer thickness range that counterbalances the effects of parasitic absorption and Ohmic/transport losses. We show that fine-tuning of the top absorber bandgap and the water layer thickness can lead to an STH efficiency increase of up to 1% absolute. Our results allow us to propose important design rules for high-efficiency photoelectrochemical devices based on multi-junction photoabsorbers.
Skip Nav Destination
Article navigation
23 August 2021
Research Article|
August 25 2021
Counterbalancing light absorption and ionic transport losses in the electrolyte for integrated solar water splitting with III–V/Si dual-junctions
Special Collection:
Materials for Renewable Fuels Production
Moritz Kölbach
;
Moritz Kölbach
1
Institute of Theoretical Chemistry, Universität Ulm
, Lise-Meitner-Str. 16, 89069 Ulm, Germany
Search for other works by this author on:
Ciler Özen;
Ciler Özen
2
Institute for Solar Fuels, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH
, Hahn-Meitner-Platz 1, 14109 Berlin, Germany
Search for other works by this author on:
Oliver Höhn
;
Oliver Höhn
3
Fraunhofer Institute for Solar Energy Systems ISE
, Heidenhofstraße 2, 79110 Freiburg, Germany
Search for other works by this author on:
David Lackner;
David Lackner
3
Fraunhofer Institute for Solar Energy Systems ISE
, Heidenhofstraße 2, 79110 Freiburg, Germany
Search for other works by this author on:
Markus Feifel
;
Markus Feifel
3
Fraunhofer Institute for Solar Energy Systems ISE
, Heidenhofstraße 2, 79110 Freiburg, Germany
Search for other works by this author on:
Fatwa F. Abdi
;
Fatwa F. Abdi
2
Institute for Solar Fuels, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH
, Hahn-Meitner-Platz 1, 14109 Berlin, Germany
Search for other works by this author on:
Matthias M. May
Matthias M. May
a)
1
Institute of Theoretical Chemistry, Universität Ulm
, Lise-Meitner-Str. 16, 89069 Ulm, Germany
a)Author to whom correspondence should be addressed: matthias.may@uni-ulm.de
Search for other works by this author on:
a)Author to whom correspondence should be addressed: matthias.may@uni-ulm.de
Note: This paper is part of the APL Special Collection on Materials for Renewable Fuels Production.
Appl. Phys. Lett. 119, 083904 (2021)
Article history
Received:
June 21 2021
Accepted:
August 12 2021
Citation
Moritz Kölbach, Ciler Özen, Oliver Höhn, David Lackner, Markus Feifel, Fatwa F. Abdi, Matthias M. May; Counterbalancing light absorption and ionic transport losses in the electrolyte for integrated solar water splitting with III–V/Si dual-junctions. Appl. Phys. Lett. 23 August 2021; 119 (8): 083904. https://doi.org/10.1063/5.0060700
Download citation file:
Sign in
Don't already have an account? Register
Sign In
You could not be signed in. Please check your credentials and make sure you have an active account and try again.
Sign in via your Institution
Sign in via your InstitutionPay-Per-View Access
$40.00