Synthesis and Evaluation of the Semiconductor Behavior in Vanadium Indanone Derivatives Thin Films

摘要

In this work, we propose a method to synthesize vanadium (IV) 2-benzyli-dene-1-indanone derivatives, used to prepare film structures by thermal evaporation. The complexes possess high melting point allowing the using of vacuum deposition methods. All the samples were grown at room temperature (25℃) and low deposition rates (0.4 Å/s). The surface morphology and structure of the deposited films were studied by scanning electron microscopy (SEM) and spectroscopy dispersive energy (EDS). Optical absorption studies of the complex films were performed in the 200 - 1100 nm wavelength range. The Tauc band gap (Eg) of the thin films was determined from the (αhν)1/2 vs. hν plots for indirect transitions. The vanadium (IV) complex films show optical activation energies in the range of organic semiconductors. Multilayer nylon 11/vanadium indanone devices were fabricated using ITO and silver electrodes. The d.c. electrical properties of the device were also investigated. It was found that the temperature-dependent electric current in the structure showed a semiconductor behavior. At lower voltages below 7 V, the current density in the forward direction was found to obey an ohmic I-V relationship;for higher voltages above 7 V, the conduction was dominated by a space-charge-limited (SCLC) mechanism. The electrical activation energies (Ea) of the complexes were in the 2.17 - 2.31 eV range.