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Efficient Water‐Splitting Device Based on a Bismuth Vanadate Photoanode and Thin‐Film Silicon Solar Cells
Author(s) -
Han Lihao,
Abdi Fatwa F.,
van de Krol Roel,
Liu Rui,
Huang Zhuangqun,
Lewerenz HansJoachim,
Dam Bernard,
Zeman Miro,
Smets Arno H. M.
Publication year - 2014
Publication title -
chemsuschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.412
H-Index - 157
eISSN - 1864-564X
pISSN - 1864-5631
DOI - 10.1002/cssc.201402456
Subject(s) - materials science , silicon , optoelectronics , energy conversion efficiency , solar cell , water splitting , bismuth vanadate , amorphous silicon , substrate (aquarium) , cadmium telluride photovoltaics , nanotechnology , crystalline silicon , chemistry , biochemistry , geology , catalysis , oceanography , photocatalysis
A hybrid photovoltaic/photoelectrochemical (PV/PEC) water‐splitting device with a benchmark solar‐to‐hydrogen conversion efficiency of 5.2 % under simulated air mass (AM) 1.5 illumination is reported. This cell consists of a gradient‐doped tungsten–bismuth vanadate (W:BiVO 4 ) photoanode and a thin‐film silicon solar cell. The improvement with respect to an earlier cell that also used gradient‐doped W:BiVO 4 has been achieved by simultaneously introducing a textured substrate to enhance light trapping in the BiVO 4 photoanode and further optimization of the W gradient doping profile in the photoanode. Various PV cells have been studied in combination with this BiVO 4 photoanode, such as an amorphous silicon (a‐Si:H) single junction, an a‐Si:H/a‐Si:H double junction, and an a‐Si:H/nanocrystalline silicon (nc‐Si:H) micromorph junction. The highest conversion efficiency, which is also the record efficiency for metal oxide based water‐splitting devices, is reached for a tandem system consisting of the optimized W:BiVO 4 photoanode and the micromorph (a‐Si:H/nc‐Si:H) cell. This record efficiency is attributed to the increased performance of the BiVO 4 photoanode, which is the limiting factor in this hybrid PEC/PV device, as well as better spectral matching between BiVO 4 and the nc‐Si:H cell.