@article{2b30348b94ec4765890a03102a538239,
title = "Stability of Chemically Doped Nanotube-Silicon Heterojunction Solar Cells: Role of Oxides at the Carbon-Silicon Interface",
abstract = "Heterojunctions of carbon nanotubes interfaced with silicon and doped with AuCl3 can achieve attractive power conversion efficiencies when operated in the photovoltaic regime; however, the cost and long-term stability of such devices must be improved before they could become commercially viable. Here, we investigate the role of chemical treatment of the carbon nanotube/silicon interface with either SOCl2 or HNO3, prior to AuCl3 doping, on the stability of the photovoltaic devices. We find that while both treatments initially lead to similar device performance, devices treated with HNO3 are significantly more stable. Using X-ray photoemission spectroscopy, we demonstrate that pretreatment with the powerful organic oxidant SOCl2 generates a variety of low-oxidation-state silicon species at the nanotube-silicon interface that are not generated by exposure to HNO3. These species and their evolution over time are implicated in the reduced device stability, highlighting the importance of silicon oxidation states in determining the stability of carbon nanotube-silicon photovoltaic devices.",
keywords = "XPS, carbon nanotubes, doping, interfacial oxide, solar cells",
author = "Tune, {Daniel D.} and Hiroyuki Shirae and Vincent Lami and Headrick, {Robert J.} and Matteo Pasquali and Yana Vaynzof and Suguru Noda and Hobbie, {Erik K.} and Flavel, {Benjamin S.}",
note = "Funding Information: The authors thank Mr. Shinpei Enomoto at Kagami Memorial Research Institute for Materials Science and Technology, Waseda University, for TEM observation. H.S. acknowledges the Leading Graduate Program in Science and Engineering, Waseda University from MEXT, Japan. B.S.F and D.D.T gratefully acknowledge support from the Deutsche Forschungsgemeinschaft (DFG) under grant numbers FL 834/2- 1, FL 834/2-2, FL 834/5-1, and FL 834/7-1. Y.V. and V.L. thank the Junior Professor Program of the Baden-W{\"u}rttemberg Ministry of Science, Research and Art for funding. M.P. acknowledges support from the Air Force Office of Scientific Research (AFOSR) (Grant No. FA9550-15-1-0370) and the Robert A. Welch Foundation (C-1668). R.J.H. was supported by a NASA Space Technology Research Fellowship (NSTRF14), grant number NNX14AL71H. Funding Information: The authors thank Mr. Shinpei Enomoto at Kagami Memorial Research Institute for Materials Science and Technology, Waseda University, for TEM observation. H.S. acknowledges the Leading Graduate Program in Science and Engineering, Waseda University from MEXT, Japan. B.S.F and D.D.T gratefully acknowledge support from the Deutsche Forschungsgemeinschaft (DFG) under grant numbers FL 834/2-1, FL 834/2-2, FL 834/5-1, and FL 834/7-1. Y.V. and V.L. thank the Junior Professor Program of the Baden-W{\"u}rttemberg Ministry of Science, Research and Art for funding. M.P. acknowledges support from the Air Force Office of Scientific Research (AFOSR) (Grant No. FA9550-15-1-0370) and the Robert A. Welch Foundation (C-1668). R.J.H. was supported by a NASA Space Technology Research Fellowship (NSTRF14), grant number NNX14AL71H. Publisher Copyright: {\textcopyright} 2019 American Chemical Society.",
year = "2019",
month = aug,
day = "26",
doi = "10.1021/acsaem.9b01050",
language = "English",
volume = "2",
pages = "5925--5932",
journal = "ACS Applied Energy Materials",
issn = "2574-0962",
publisher = "American Chemical Society",
number = "8",
}
