Determination of critical island size inpara-sexiphenyl islands on SiO2using capture-zone scaling

Abstract

One of the important parameters in understanding the mechanism of the early stage of organic thin-film growth is the critical nucleus size i*. Here, submonolayer films of para-sexiphenyl grown on amorphous silicon dioxide substrates were investigated by means of atomic-force microscopy and have been analyzed using the recently proposed capture-zone scaling. Applying the generalized Wigner surmise we determine from the capture-zone distribution i* at room temperature and 373 K. The results are compared to traditional analysis by island-size scaling and the applicability of the capture-zone scaling is critically discussed with respect to island shape.