p-polarized infrared attenuated total reflection study of InN thin films grown on Si(111) substrate

We report for the first time the surface phonon polariton (SPP) and interface phonon polariton (IPP) characteristics of InN thin films grown on AlN buffer layer on Si(111) substrate by molecular beam epitaxy. The p-polarized infrared attenuated total reflection technique was used to excite the SPP and IPP modes of the sample. It was found that the SPP mode of InN and the IPP mode of InN/AlN were clearly ob- served at 609 cm-1 and 877 cm-1, respectively. The origins of the observed peaks were verified by theoretical simulations based on the anisotropic model. In general, a good agreement between the experimental and theoretical results was obtained. Finally, the effect of the free carriers on the SPP mode is discussed. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)