Visible light is emitted from the Au-air interface of Al-I-Au thin-film tunnel junctions (deposited over a thin layer of CaF2 on glass) as a result of the decay of surface plasmon polaritons (SPPs). We show the surface topography of such a Au film and relate its large-scale features to the outcoupling of fast SPP's to photons. The absence of short-scale roughness features is explained by thier disappearance through surface diffusion. To confirm this a controlled sequence of 5-nm, 20-ms scanning tunneling microscope (STM) W tip crashes has been used to produce indentations 3 nm deep with a lateral dimension of 5-7 nm on a Au crystal in air at room temperature. Four sequences of indentations were drawn in the form of a square box. Right from the start, feature decay is observed and over a period of 2 h a succession of images shows that the structure disappears into the background as a result of surface diffusion. The surface diffusion constant is estimated to be 10(-18) cm2 s-1. The lack of light output via slow mode SPPs is an inevitable consequence of surface annealing.
|Number of pages||4|
|Journal||Journal of vacuum science & technology b|
|Publication status||Published - 1991|
|Event||5TH INTERNATIONAL CONF ON SCANNING TUNNELING MICROSCOPY/SPECTROSCOPY ( STM 90 ) / 1ST INTERNATIONAL CONF ON NANOMETER SCALE SCIENCE AND TECHNOLOGY ( NANO 1 ) - BALTIMORE, Moldova, Republic of|
Duration: 23 Jul 1990 → 27 Jul 1990