Improving the Back Surface Field on an Amorphous Silicon Carbide Thin-Film Photocathode for Solar Water Splitting.

Autor: Perez-Rodriguez P; Photovoltaic Materials and Devices (PVMD) group, Delft University of Technology, Delft, The Netherlands., Cardenas-Morcoso D; Institute of Advanced Materials (INAM), Universitat Jaume I, 12006, Castelló de la Plana, Spain., Digdaya IA; Materials for Energy Storage and Conversion (MECS), Department of Chemical Engineering, Delft University of Technology, Delft, The Netherlands., Raventos AM; Photovoltaic Materials and Devices (PVMD) group, Delft University of Technology, Delft, The Netherlands., Procel P; Photovoltaic Materials and Devices (PVMD) group, Delft University of Technology, Delft, The Netherlands., Isabella O; Photovoltaic Materials and Devices (PVMD) group, Delft University of Technology, Delft, The Netherlands., Gimenez S; Institute of Advanced Materials (INAM), Universitat Jaume I, 12006, Castelló de la Plana, Spain., Zeman M; Photovoltaic Materials and Devices (PVMD) group, Delft University of Technology, Delft, The Netherlands., Smith WA; Materials for Energy Storage and Conversion (MECS), Department of Chemical Engineering, Delft University of Technology, Delft, The Netherlands., Smets AHM; Photovoltaic Materials and Devices (PVMD) group, Delft University of Technology, Delft, The Netherlands.
Jazyk: angličtina
Zdroj: ChemSusChem [ChemSusChem] 2018 Jun 11; Vol. 11 (11), pp. 1797-1804. Date of Electronic Publication: 2018 May 09.
DOI: 10.1002/cssc.201800782
Abstrakt: Amorphous silicon carbide (a-SiC:H) is a promising material for photoelectrochemical water splitting owing to its relatively small band-gap energy and high chemical and optoelectrical stability. This work studies the interplay between charge-carrier separation and collection, and their injection into the electrolyte, when modifying the semiconductor/electrolyte interface. By introducing an n-doped nanocrystaline silicon oxide layer into a p-doped/intrinsic a-SiC:H photocathode, the photovoltage and photocurrent of the device can be significantly improved, reaching values higher than 0.8 V. This results from enhancing the internal electric field of the photocathode, reducing the Shockley-Read-Hall recombination at the crucial interfaces because of better charge-carrier separation. In addition, the charge-carrier injection into the electrolyte is enhanced by introducing a TiO 2 protective layer owing to better band alignment at the interface. Finally, the photocurrent was further enhanced by tuning the absorber layer thickness, arriving at a thickness of 150 nm, after which the current saturates to 10 mA cm -2 at 0 V vs. the reversible hydrogen electrode in a 0.2 m aqueous potassium hydrogen phthalate (KPH) electrolyte at pH 4.
(© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)
Databáze: MEDLINE
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