TY - JOUR
T1 - Improving the Back Surface Field on an Amorphous Silicon Carbide Thin Film Photocathode for Solar Water Splitting
AU - Perez-Rodriguez, Paula
AU - Cardenas-Morcoso, Drialys
AU - Digdaya, Ibadillah A.
AU - Raventos, Andrea Mangel
AU - Procel, Paul
AU - Isabella, Olindo
AU - Gimenez, Sixto
AU - Zeman, Miro
AU - Smith, Wilson A.
AU - Smets, Arno H.M.
N1 - Accepted Author Manuscript
PY - 2018
Y1 - 2018
N2 - 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.
AB - 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.
KW - Charge carrier injection
KW - Hydrogen
KW - Silicon carbide
KW - Titanium dioxide
KW - Water splitting
UR - http://resolver.tudelft.nl/uuid:bc66f5e5-dd4f-4cbb-9988-5d3ebd5d5630
UR - http://www.scopus.com/inward/record.url?scp=85046554102&partnerID=8YFLogxK
U2 - 10.1002/cssc.201800782
DO - 10.1002/cssc.201800782
M3 - Article
AN - SCOPUS:85046554102
VL - 11
SP - 1797
EP - 1804
JO - ChemSusChem (Print): chemistry & sustainability, energy & materials
JF - ChemSusChem (Print): chemistry & sustainability, energy & materials
SN - 1864-5631
IS - 11
ER -