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

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

Perez Rodriguez, P. (TU Delft Photovoltaic Materials and Devices)
Cardenas-Morcoso, Drialys (Universitat Jaume I)
Digdaya, I.A. (TU Delft ChemE/Materials for Energy Conversion and Storage)
Mangel Raventos, A. (TU Delft Photovoltaic Materials and Devices)
Procel Moya, P.A. (TU Delft Photovoltaic Materials and Devices)
Isabella, O. (TU Delft Photovoltaic Materials and Devices)
Gimenez, Sixto (Universitat Jaume I)
Zeman, M. (TU Delft Electrical Sustainable Energy)
Smith, W.A. (TU Delft ChemE/Materials for Energy Conversion and Storage)
Smets, A.H.M. (TU Delft Photovoltaic Materials and Devices)

Electrical Sustainable Energy

2018

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 0.8V. 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 TiO₂ 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 150nm, after which the current saturates to 10mAcm^-2 at 0V vs. the reversible hydrogen electrode in a 0.2m aqueous potassium hydrogen phthalate (KPH) electrolyte at pH4.

Charge carrier injection
Hydrogen
Silicon carbide
Titanium dioxide
Water splitting

http://resolver.tudelft.nl/uuid:bc66f5e5-dd4f-4cbb-9988-5d3ebd5d5630

https://doi.org/10.1002/cssc.201800782

2019-04-25

1864-5631

ChemSusChem (Print): chemistry & sustainability, energy & materials, 11 (11), 1797-1804

Accepted Author Manuscript

Institutional Repository

journal article

© 2018 P. Perez Rodriguez, Drialys Cardenas-Morcoso, I.A. Digdaya, A. Mangel Raventos, P.A. Procel Moya, O. Isabella, Sixto Gimenez, M. Zeman, W.A. Smith, A.H.M. Smets