abstract
Ni(dcbdt)(2)-based molecular materials, namely [(n-C4H9)(4)N](2)[Ni(dcbdt)(2)](5), and (BEDT-TTF)[Ni(dcbdt)(2)] have been processed as microcrystalline films on (001)-oriented silicon substrates using the electrodeposition technique [dcbdt(2-): 4,5-dicyanobenzene-1,2-dithiolato; BEDT-TTF: bis(ethylenedithio) tetrathiafulvalene]. Electrodeposited [(n-C4H9)(4)N](2)[Ni(dcbdt)(2)](5) is made of thin platelets. Elemental analysis and X-ray photoelectron spectroscopy data are in agreement with a 2 : 5 stoichiometry. X-Ray powder diffraction measurements indicate that the growth is highly anisotropic, the ab-plane being parallel to the silicon surface. The films exhibit a semiconducting behaviour with a room-temperature conductivity of about 1.2 x 10(-2) S cm(-1). Electrodeposition run in the presence of the BEDT-TTF donor molecule leads to faceted microcrystals ( size: 5 - 100 mum) of (BEDT-TTF)[Ni(dcbdt)(2)] as evidenced by scanning electron microscopy. Single crystal data show that this new (BEDT-TTF)[Ni(dcbdt)(2)] phase is isostructural to the previously described (BEDT-TTF)[Au(dcbdt)(2)]. Again, elemental analysis and X-ray photoelectron spectroscopy data are in agreement with a 1 : 1 stoichiometry. The room-temperature conductivity of the film is about 3 x 10(-6) S cm(-1). This low value is comparable to that measured on (BEDT-TTF)[Au(dcbdt)(2)] single crystals. For both materials the charge transfer is similar, as consistently evaluated from Raman, infrared and photoemission measurements.
keywords
CHARGE-TRANSFER SALTS; TCNQ THIN-FILMS; COMPLEXES; CVD; PERSPECTIVES; PRECURSORS
subject category
Chemistry; Materials Science
authors
de Caro, D; Alves, H; Almeida, M; Caillieux, S; Elgaddari, M; Faulmann, C; Malfant, I; Senocq, F; Fraxedas, J; Zwick, A; Valade, L
our authors
