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New Findings from V. Seshan and Co-Researchers in the Area of Boron Described (Contactless Photoconductance Study on Undoped and Doped...

September 2, 2014



New Findings from V. Seshan and Co-Researchers in the Area of Boron Described (Contactless Photoconductance Study on Undoped and Doped Nanocrystalline Diamond Films)

By a News Reporter-Staff News Editor at Life Science Weekly -- Research findings on Boron are discussed in a new report. According to news reporting from Diepenbeek, Belgium, by NewsRx journalists, research stated, "Hydrogen and oxygen surface-terminated nanocrystalline diamond (NCD) films are studied by the contactless time-resolved microwave conductivity (TRMC) technique and X-ray photoelectron spectroscopy (XPS). The optoelectronic properties of undoped NCD films are strongly affected by the type of surface termination."

The news correspondents obtained a quote from the research, "Upon changing the surface termination from oxygen to hydrogen, the TRMC signal rises dramatically. For an estimated quantum yield of 1 for sub-bandgap optical excitation the hole mobility of the hydrogen-terminated undoped NCD was found to be similar to 0.27 cm(2)/(V s) with a lifetime exceeding 1 mu s. Assuming a similar mobility for the oxygen-terminated undoped NCD a lifetime of similar to 100 ps was derived. Analysis of the valence band spectra obtained by XPS suggests that upon oxidation of undoped NCD the surface Fermi level shifts (toward an increased work function). This shift originates from the size and direction of the electronic dipole moment of the surface atoms, and leads to different types of band bending at the diamond/air interface in the presence of a water film. In the case of boron-doped NCD no shift of the work function is observed, which can be rationalized by pinning of the Fermi level. This is confirmed by TRMC results of boron-doped NCD, which show no dependency on the surface termination."

According to the news reporters, the research concluded: "We suggest that photoexcited electrons in boron-doped NCD occupy nonionized boron dopants, leaving relatively long-lived mobile holes in the valence band."

For more information on this research see: Contactless Photoconductance Study on Undoped and Doped Nanocrystalline Diamond Films. ACS Applied Materials & Interfaces, 2014;6(14):11368-11375. ACS Applied Materials & Interfaces can be contacted at: Amer Chemical Soc, 1155 16TH St, NW, Washington, DC 20036, USA. (American Chemical Society - www.acs.org; ACS Applied Materials & Interfaces - www.pubs.acs.org/journal/aamick)

Our news journalists report that additional information may be obtained by contacting V. Seshan, IMEC Vzw, IMOMEC, BE-3590 Diepenbeek, Belgium. Additional authors for this research include D.H.K. Murthy, A. Castellanos-Gomez, S. Sachdeva, H.A. Ahmad, S.D. Janssens, W. Janssen, K. Haenen, H.S.J. van der Zant, E.J.R. Sudholter, T.J. Savenije and L. de Smet (see also Boron).

Keywords for this news article include: Boron, Europe, Belgium, Diepenbeek, Nanotechnology, Nanocrystalline, Emerging Technologies

Our reports deliver fact-based news of research and discoveries from around the world. Copyright 2014, NewsRx LLC


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Source: Life Science Weekly


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