Molecular arrangement of organic crystal N,N '-dimethylperylene-3,4,9,10-bis(dicarboximide) studied with metastable de-excitation spectroscopy and atomic force microscopy

We have studied the molecular orbitals and arrangements of N,N'-dimethylper ylene-3,4,9,10-bis(dicarboximide) (Me-PTC) molecules deposited on clean Si( 100)2 x 1 and the H-terminated Si(100) surfaces on the basis of metastable de-excitation spectroscopy (MDS) experiments. The charge density of the sec ond layer Me-PTC molecular orbitals differs somewhat from that of the first layer. The desorption temperature of Me-PTC from H-terminated Si surface i s lower than that from clean Si. This is because Me-PTC molecules combine w eakly with the H-terminated Si substrate. (C) 1999 Elsevier Science S.A. Al l rights reserved.