Surface modification of a-SiC photoelectrodes for photocurrent enhancement

Ilvydas Matulionis; Jian Hu; Feng Zhu; Josh Gallon; Nicolas Gaillard; Todd Deutsch; Eric Miller; Arun Madan

doi:10.1117/12.860669

24 August 2010 Surface modification of a-SiC photoelectrodes for photocurrent enhancement

Ilvydas Matulionis, Jian Hu, Feng Zhu, Josh Gallon, Nicolas Gaillard, Todd Deutsch, Eric Miller, Arun Madan

Proceedings Volume 7770, Solar Hydrogen and Nanotechnology V; 77700Z (2010) https://doi.org/10.1117/12.860669
Event: SPIE Solar Energy + Technology, 2010, San Diego, California, United States

Abstract

Photoelectrochemical (PEC) water dissociation into hydrogen and oxygen at a semiconductor-liquid interface offers an environmentally benign approach to hydrogen production. We have developed an integrated PEC device using hydrogenated amorphous silicon carbide (a-SiC or a-SiC:H) material as photoelectrode in conjunction with an amorphous silicon (a-Si) tandem photovoltaic device. Such a "hybrid PV/a-SiC" PEC cell produces photocurrent of about 1.3 mA/cm² in a short-circuit configuration and is durable in a pH2 electrolyte. On the other hand, the aforementioned structure finished with ITO contacts and measured as a solid-state device features a current density of 5 mA/cm², indicating a potential solar-to-hydrogen (STH) conversion efficiency of about 6% in the hybrid PV/a-SiC PEC cell. The much lower photocurrent measured in the hybrid PEC cell suggests that there exists an interfacial barrier between the a-SiC and electrolyte, which hinders the photocurrent extraction. In order to mitigate against the interfacial barrier and hence improve the photo-generated charge carrier transport through the a-SiC/electrolyte interface, we have explored several surface modification techniques, namely the use of metallic nano-particles (such as platinum or palladium) and the growth of an additional thin layer (a-SiNx, carbon-rich a-SiC, a-SiF, etc.) on the top of a-SiC by PECVD. In the latter case, it is observed that the addition of a thin PECVD-fabricated layer does not significantly improve the photocurrent, presumably due to a poor band alignment at the a-SiC/electrolyte interface. The use of lower work function nanoparticles like titanium has led to promising results in terms of photocurrent enhancement and an a nodic shift in the onset potential.

Citation Download Citation

Ilvydas Matulionis, Jian Hu, Feng Zhu, Josh Gallon, Nicolas Gaillard, Todd Deutsch, Eric Miller, and Arun Madan "Surface modification of a-SiC photoelectrodes for photocurrent enhancement", Proc. SPIE 7770, Solar Hydrogen and Nanotechnology V, 77700Z (24 August 2010); https://doi.org/10.1117/12.860669

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available