Growth dynamics of C60 thin films: Effect of molecular structure

Abstract

The surface morphology and growth behavior of fullerene thin films have been studied by atomic force microscopy and height difference correlation function analysis. In contrast to the large growth exponents (β) previously reported for other organic semiconductor thin-film materials, a relatively small β value of 0.39±0.10 was determined. Simulations of (1+1)-dimensional surface lateral diffusion models indicate that the evolution of deep grain boundaries leads to a rapid increase in β. We suggest that the commonly observed large β values for organic thin films are due to their intrinsically anisotropic molecular structures and hence different stacking directions between crystallite domains.

Structural templating and growth behavior of copper phthalocyanine thin films deposited on a polycrystalline perylenetetracarboxylic dianhydride layer

“…As the CuPc film thickness increased, all the peaks became more apparent [Figs. 19,20 IV. The peak at 2h ¼ 26.62 , next to the PTCDA(102) peak at 2h ¼ 27.62 , has been extensively shown to be the peak caused by surface-parallel stacking of CuPc molecules, i.e., the structurally templated CuPc layer [ Fig.…”

Thermally‐activated post‐growth dewetting of fullerene C60 on mica

“…The thin film morphology is a key parameter for an optimized design of organic heterostructures and organic devices with high performance . The morphology formation of organic thin films can be controlled by templating or epitaxial relations with the substrate as well as the choice of growth conditions , but post‐growth dynamics, such as the break‐up of a smooth thin film into islands, are crucial both for further processing steps as well as for the long‐term device stability . Post‐growth reorganization is particularly common for molecular soft matter films and has been observed for several technologically relevant molecular materials including diindenoperylene , pentacene and fullerene C 60 .…”

Study on Anomalous Scaling Exponents for Molecular Thin Film Growth Using Surface Lateral Diffusion Model

“…4 In contrast to well-studied atomic-based inorganic thin films, however, current knowledge on the growth mechanism of molecular thin films is limited. Recently several studies have attempted to understand the growth behavior of molecular thin films, using a scaling theory, [5][6][7][8] which is a commonly used method for studying the growth dynamics of inorganic thin film systems. [9][10][11][12] These studies were carried out using a combination of experimental scanning probe methods such as atomic force microscopy (AFM) and theoretical scaling calculations such as height difference correlation function (HDCF) analysis, which provides a variety of scaling exponents, such as roughness (α), growth (β) and dynamic (z) exponent, and the relationship between them.…”

“…In the case of molecular thin films, however, a broad range of significantly smaller ρ values have been reported such as the case for 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA) (ρ = 0.33), 6 zinc phthalocyanine (ZnPc) (ρ = 0.54) 8 and C 60 (ρ = 0.67). 7 The surface morphology evolutions for the PTCDA and C 60 thin films shown in Figure 1 seemed to be related to the ρ values, i.e. the smaller the ρ value, the spikier the film grows.…”

“…The evolution of surface morphologies of each molecular thin film system was well described in the literatures. [6][7][8]14 The step-edge barriers (ΔE b ) for the molecular thin films were determined by intermolecular interaction energy calculations using molecular mechanics (MM) force field parameters, which were well described elsewhere.…”