Amorphous Si (a-Si)/crystalline Si (c-Si) heterojunction (SiHJ) can serve as highly efficient and robust photoelectrodes for solar fuel generation. Low carrier recombination in the photoelectrodes leads to high photocurrents and photovoltages. The SiHJ was designed and fabricated into both photoanode and photocathode with high oxygen and hydrogen evolution efficiency, respectively, by simply coating of a thin layer of catalytic materials. The SiHJ photoanode with sol-gel NiOx as the catalyst shows a current density of 21.48 mA/cm2 at the equilibrium water oxidation potential. The SiHJ photocathode with 2 nm sputter-coated Pt catalyst displays excellent hydrogen evolution performance with an onset potential of 0.640 V and a solar to hydrogen conversion efficiency of 13.26%, which is the highest ever reported for Si-based photocathodes. © 2015 American Chemical Society.
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledgements: D.W. acknowledges the financial support for this work by the National Science Foundation (CBET1236155). D.W. thanks Drs. R. Rao and B. Fruhberger from Qualcomm Institute of UCSD for their unconditional support. The authors thank the staff of UCSD Nano3 facilities for their timely and professional support. The authors acknowledge KAUST, National Science Council of Taiwan and National Taiwan University.
ASJC Scopus subject areas
- Materials Science(all)
- Mechanical Engineering
- Condensed Matter Physics