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Abstract: In this paper we present photoemission studies of the influence of 12-hour exposure to the ambient air on the chemical and electronic properties of thin 16-nm copper phthalocyanine (CuPc) sensing layers deposited on n- and p-type silicon Si(111) substrates covered with the native oxide. The surface chemistry and electronic parameters of organic thin film including surface band bending, work function, electron affinity and their variations upon the exposure have been monitored with X-ray photoemission spectroscopy and ultraviolet photoemission spectroscopy techniques. We found that after the exposure, the surface chemistry of CuPc remained unaffected, however the work function and surface band bending increased by 0.55eV and 0.45eV for the layers on n-Si and by 0.25eV and 0.30eV for those on p-Si. Additionally, we detected a slight surface dipole at CuPc on n-Si manifested by a small shift in electron affinity of 0.10eV. In order to explain these changes we developed a model basing on the interaction of ionic species with the phthalocyanine surface. [ABSTRACT FROM AUTHOR]

Abstract: Herein investigation of the effects of substrate temperature on the structural and morphological features of both cobalt(II) phthalocyanine (CoPc) and cobalt(II) hexadecafluorophthalocyanine (CoPcF16) thin films is presented. For these purposes thin films of CoPc and CoPcF16 prepared by organic molecular beam deposition were investigated by means of optical absorption spectroscopy, X-ray diffraction, Raman spectroscopy, and atomic force microscopy. Concerning the degree of crystallinity, the morphology, the phase composition and the preferential molecular orientation of both CoPc and CoPcF16 thin films, we found out that the increase of substrate temperature during growth influences these properties of the above-mentioned thin film systems (CoPc vs. CoPcF16) in a different way. [ABSTRACT FROM AUTHOR]

Abstract: In this paper native and RCA-treated n- and p-doped Si(111) substrates and ultra-thin 16-nm copper phthalocyanine (CuPc) layers deposited thereon were investigated using X-ray Photoemission Spectroscopy and Angle-Resolved X-ray Photoemission Spectroscopy. The oxide layer thickness was determined to be 1.3nm on the RCA-treated substrates and 0.8nm on the native ones. The analysis of substrate carbon contamination showed the existence of C–H, C–OH and COOH components on all substrates. The RCA clean removes more readily the carbon components with the OH group from the n-type Si and causes the segregation of the contaminants. The initial carbon species propagate in the evaporated CuPc layer up to a thickness of about 5nm affecting the shape of the C1s peak. Additionally, the behavior of the binding energy difference between N1s and Si2p peaks upon the CuPc growth shows that there may occur various CuPc molecule adsorption modes on investigated Si substrates. It could be a useful information, from the technological point of view, especially for low dimensional electronic device preparation. [Copyright &y& Elsevier]