Metal Nanoantenna Plasmon Resonance Lineshape Modification By Semiconductor Surface Native Oxide

We present reflectivity spectra of gold nanoantenna arrays fabricated directly onto GaAs substrates, which exhibit highly asymmetric line-shapes close to the localised surface plasmon resonance wavelength. Using detailed scattering matrix simulations, we show that the asymmetry is caused by an interference effect that is enhanced by the presence of a thin (few nm) native oxide layer on the GaAs surface. Our results have important implications for the correct design of nanoplasmonic systems for enhanced incoupling of light in semiconductor-based photovoltaic systems. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4748298]