Influence of intermolecular interactions on the structure of phthalocyanine layers in molecular thin film heterostructures

Abstract

The surface structures of copper phthalocyanine (CuPc) thin films deposited on sulphur-passivated and plane perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA)-covered InAs(100) surfaces have been studied by low energy electron diffraction (LEED) and van der Waals (vdW) intermolecular interaction energy calculations. The annealing to 300 o C and 450 o C of (NH4)2Sx-treated InAs(100) substrates produces a (1×1) and (2×1) S-passivated surface respectively. The CuPc deposition onto the PTCDA-covered InAs(100) surface leads to a ring-like diffraction pattern, indicating that the 2D ordered overlayer exists and the structure is dominantly determined by the intermolecular interactions rather than substrate-molecule interactions. However, no ordered LEED patterns were observed for the CuPc on S-passivated InAs(100) surface. The intermolecular interaction energy calculations have been carried out to rationalise this structural difference. In the case of CuPc unit cells on PTCDA layer, the planar layered CuPc structure is more stable than the α-herringbone structure, consistent with the experimental LEED results. For CuPc unit cells on a S-(1×1) layer, however, the α-herringbone structure is more stable than the planar layered structure, consistent with the absence of diffraction pattern. The results show that the lattice structure during the initial stages of thin film growth is influenced strongly by the intermolecular interactions at the interface.

Substrate-controlled ferromagnetism in iron phthalocyanine films due to one-dimensional iron chains

“…31 This peak translates to a Bragg d-spacing of 3.20Å. The absence of the low-angle peaks suggests that the molecules order with their planes parallel to the substrate plane so that the b-axis is close to perpendicular to the substrate plane as shown in Fig.…”

Highly unquenched orbital moment in textured Fe-phthalocyanine thin films

“…12 The thin film sample in this work was prepared in an organic molecular beam epitaxy ͑OMBE͒ system. SigmaAldrich FePc was purified in three cycles using the temperature gradient method.…”

Inhomogeneous charge transfer within monolayer zinc phthalocyanine absorbed on TiO2(110)

“…[3][4][5] Therefore, much efforts have been put into understanding the system of phthalocyanines on various substrates: semiconductors, 5 metals [6][7][8] and organic layers. [9][10][11] Meanwhile, scientists try to establish a "universal rule" for the interaction between organics, especially Pc, and semiconductor substrate based on theoretical calculations. 3,4 In the past two decades, the oxide/organic interface, especially in the field of photovoltaics, 1,12 has attracted much interest.…”