Atomically-Flat Nanosurface Arrays for STM and Photonic Studies

Flat gold nanoparticles (FGNPs) can be used as atomically-flat gold substrates for STM studies. When supported on ITO coated glass the FGNPs can also be used as atomically-flat photonic substrates. Transmission electron microscopy (TEM) shows that FGNP's can be prepared 100--500 nm across with shapes that range from triangular to hexagonal with thicknesses of 15-25 nm. Dark-field optical microscopy is a convenient method for evaluating the FGNP arrays because the FGNPs and spherical gold nanoparticles are distinguished easily. STM and AFM reveal atomically flat terraces on the large {\{}111{\}} FGNP facets. An optimized method for growing the FGNPs and for depositing them on ITO coated glass with a high particle density is presented.\textbf{ }