Electrical and optical properties of Jäger-nickel (II)-based molecular-material thin films prepared by the vacuum thermal evaporation technique

• Published in: The Journal of physics and chemistry of solids Vol. 68; no. 8; pp. 1571 - 1582
• Main Authors: Morales-Saavedra, O.G., Sánchez Vergara, M.E., Ortiz Rebollo, A., Ortega-Martínez, R.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.08.2007; Elsevier
• Subjects: A. Thin films; B. Chemical synthesis; Condensed matter: electronic structure, electrical, magnetic, and optical properties; D. Electrical properties; D. Optical properties; D. Semiconductivity; Exact sciences and technology; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of specific thin films; Physics; Polymers; organic compounds; B. Chemical synthesis; A. Thin films; D. Optical properties; D. Semiconductivity; D. Electrical properties; Atomic force microscopy; Semiconductor materials; Surface morphology; Photoluminescence; Molecular crystals; XRD; Infrared spectra; Ellipsometry; Thin films; Thickness; Ultraviolet radiation; Optical properties; Fourier transform spectra; Third harmonic generation; Vacuum evaporation
• ISSN: 0022-3697; 1879-2553
• DOI: 10.1016/j.jpcs.2007.03.040

Semiconductor molecular-material thin films of [6,13-Ac 2-5,14-Me 2-[14]-4,6,11,13-tetraenato-1,4,8,11-N 4] and the bidentate amines 1,4-diaminebutane, 1,12-diaminedodecane and 2,6-diamineanthraquinone have been prepared by vacuum thermal evaporation on corning glass substrates and crystalline silicon wafers. The films thus obtained were characterized by infrared (FTIR), ultraviolet–visible (UV–VIS) and photoluminescence (PL) spectroscopies. The surface morphology, thickness and structure of these films were analyzed by atomic force microscopy (AFM), ellipsometry and X-ray diffraction (XRD), respectively. IR spectroscopy showed that the molecular-material thin films exhibit the same intra-molecular bonds as the original compounds, which suggests that the thermal evaporation process does not significantly alter their bonds. The effect of temperature on conductivity was also measured in these samples; it was found that the temperature-dependent electric current is always higher for the voluminous amines with large molecular weights and suggests a semiconductor behavior with conductivities in the order of 10 −6–10 −1 Ω −1 cm −1. Finally, the optical band gap ( E g) and cubic χ (3) non-linear optical (NLO) properties of these amorphous molecular complexes were also evaluated from optical absorption and optical third harmonic generation (THG) measurements, respectively.