Low temperature scanning tunneling microscopy (LT-STM) and spectroscopy (STS) have been used to investigate the growth of Cu-phthalocyanine (C32H16N8Cu) molecules on an ultrathin Al2O3 oxide film grown on the Ni3Al(111) surface [1] as a function of coverage and annealing temperature. For sub- and monolayer coverage and a deposition temperature of 140 K two different planar molecular adsorption configurations rotated by 30o with respect to each other were observed with sub molecular resolution in the STM images. For Q CuPc» 1 ML, before completion of the first layer, the growth of a second layer was already observed. The measured distance of 3.5 Ǻ between 1st and 2nd layer corresponds to the distance between layers in the a modification of crystalline CuPc. By the use of STS’ the lowest unoccupied molecular orbital (LUMO) of the adsorbed CuPc molecules has been identified at an energy of 1.2 eV. The lateral distribution of the electronic states of the CuPc has been analysed and mapped by STS. The C32H16N8Cu molecules grown at 140 are thermal stable up to 350 K against shape changes upon prolonged annealing to temperatures up to 350 K. A template effect of the underlying oxide film on the CuPc growth, as has been observed for metals like Pd [2], has not been found.
[1] S. Degen, A. Krupski, M. Kralj, A. Langner, C. Becker, M. Sokolowski and K. Wandelt, Surf. Sci. Lett. 576 (2005) L57-L64.
[2] S. Degen, C. Becker and K. Wandelt, Faraday Discuss. 125 (2003) 343.

• Legal notice:
  

  Copyright (c) Pielaszek Research, all rights reserved.
  The above materials, including auxiliary resources, are subject to Publisher's copyright and the Author(s) intellectual rights. Without limiting Author(s) rights under respective Copyright Transfer Agreement, no part of the above documents may be reproduced without the express written permission of Pielaszek Research, the Publisher. Express permission from the Author(s) is required to use the above materials for academic purposes, such as lectures or scientific presentations.
  In every case, proper references including Author(s) name(s) and URL of this webpage: https://science24.com/paper/8711 must be provided.