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A High Efficiency Si Photoanode Protected by Few‐Layer MoSe 2
Author(s) -
Vanka Srinivas,
Wang Yongjie,
Ghamari Pegah,
Chu Sheng,
Pandey Ayush,
Bhattacharya Pallab,
Shih Ishiang,
Mi Zetian
Publication year - 2018
Publication title -
solar rrl
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.544
H-Index - 37
ISSN - 2367-198X
DOI - 10.1002/solr.201800113
Subject(s) - photocurrent , materials science , layer (electronics) , substrate (aquarium) , optoelectronics , reversible hydrogen electrode , electrode , molecular beam epitaxy , current density , semiconductor , epitaxy , nanotechnology , working electrode , electrochemistry , chemistry , geology , oceanography , physics , quantum mechanics
To date, the performance of semiconductor photoanodes has been severely limited by oxidation and photo‐corrosion. Here, a report is given on the use of earth‐abundant MoSe 2 as a surface protection layer for Si‐based photoanodes. Large area MoSe 2 film was grown on p + ‐n Si substrate by molecular beam epitaxy. It is observed that the incorporation of few‐layer (≈3 nm) epitaxial MoSe 2 can significantly enhance the performance and stability of Si photoanode. The resulting MoSe 2 / p + ‐n Si photoanode produces a light‐limited current density of 30 mA cm −2 in 1 M HBr under AM 1.5G one sun illumination, with a current‐onset potential of 0.3 V versus reversible hydrogen electrode (RHE). The applied bias photon‐to‐current efficiency (ABPE) reaches up to 13.8%, compared to the negligible ABPE values (<0.1%) for a bare Si photoanode under otherwise identical experimental conditions. The photoanode further produced stable voltage of ≈0.38 V versus RHE at a photocurrent density of ≈2 mA cm −2 for ≈14 h under AM 1.5G one sun illumination. This work shows the extraordinary potential of two‐dimensional transitional metal dichalcogenides in photoelectrochemical application and will contribute to the development of low cost, high efficiency, and highly stable Si‐based photoelectrodes for solar hydrogen production.