Epitaxial growth of copper phthalocyanine on a large single-grain of thin film alkyl perylene diimide

Abstract

In this work, heteroepitaxial growth of copper phthalocyanine (CuPc) on a large single-grain of thin film N,N'-Di-n-octyl-3,4,9,10-perylenetetracarboxylic diimide (PTCDI-C8) was investigated. Vacuum-deposited PTCDI-C8 thin films at a growth temperature of ~180 °C exhibited large grain growth of several hundred micrometers or more in size, and their surface consisted of stripe islands with molecular steps. CuPc deposited at 180 °C on this PTCDI-C8 large grain underlayer was found to grow epitaxially with its needle-like crystals dominantly oriented in one unique direction. The mechanism of the observed epitaxy is discussed based on the results of in-plane X-ray diffraction and the initial growth morphology.