Influence of substrate on molecular order for self‐assembled adlayers of CoPc and FePc. (12th February 2018)

• Record Type: Journal Article
• Authors: Kumar, Abhishek; Naumenko, Denys; Cozzarini, Luca; Barba, Luisa; Cassetta, Alberto; Pedio, Maddalena
• Other Names: Rossi Barbara guestEditor.; Masciovecchio Claudio guestEditor.
• Is Part Of: Journal of Raman spectroscopy. Volume 49:Number 6(2018)
• Page Start: 1015
• Page End: 1022
• Publication Date: 2018-02-12
• Subjects: metal phthalocyanine thin films -- molecular stacking -- molecule–substrate interactions -- Raman spectroscopic analysis; Raman spectroscopy -- Periodicals; 535.846
• DOI: 10.1002/jrs.5344
• Languages: English
• ISSNs: 0377-0486

Abstract

Abstract: Self‐assembled metal phthalocyanine thin films are receiving considerable interest due to their potential technological applications. In this study, we present a comprehensive study of CoPc and FePc thin films of about 50 nm thickness on technologically relevant substrates such as SiOx /Si, indium tin oxide (ITO) and polycrystalline gold in order to investigate the substrate induced effects on molecular stacking and crystal structure. Raman spectroscopic analysis reveals lower intensity for the vibrational bands corresponding to phthalocyanine macrocycle for the CoPc and FePc thin films grown on ITO as compared to SiOx /Si due to the higher order of phthalocyanine molecules on SiOx /Si. Atomic force microscopy analysis displays higher grain size for FePc and CoPc thin films on ITO as compared to SiOx /Si and polycrystalline gold indicating towards the influence of molecule–substrate interactions on the molecular stacking. Grazing incidence X‐ray diffraction reciprocal space maps reveal that FePc and CoPc molecules adopt a combination of herringbone and brickstone arrangement on SiOx /Si and polycrystalline gold substrate, which can have significant implications on the optoelectronic properties of the films due to unique molecular stacking. Abstract : Raman spectroscopic analysis of FePc and CoPc thin films of about 50 nm thickness deposited on polycrystalline gold, SiOx /Si, and indium tin oxide (ITO) substrates reveals lower intensity for macrocycle breathing mode at 685 cm ‐1 for films grown on ITO as compared to SiOx /Si due to the higher order of phthalocyanine molecules on SiOx /Si. Grazing incidence X‐ray diffraction analysis indicates that CoPc and FePc thin films deposited on ITO are the least ordered.