Structural, optical and electrical properties of Ni(II)-2,2-bipyridine complexes thin films deposited on glass substrates

The present study was mainly designed to prepare thin layers based on hybrid materials deposited on glass substrates. Herein, the Ni(II)-2,2-bipyridine complexes thin films have been elaborated following a successive ionic layer adsorption and reaction process as a simple and low-cost chemical technique. The deposition experiments were performed on glass substrates under the effect of several physicochemical factors, including dipping cycles (30–120 cycles), variations in solution temperature (293–323 K) and in precursor concentrations (10−3–10−1 mol L−1), as well as the effect of the counter-anions [Fe(CN)5NO]−2 and [Ag(CN)2]−. The synthesized films were characterized using scanning electron microscopy, Fourier Transform Infrared Spectroscopy, electrical resistivity and optical microscopy methods. It revealed an optical band gap energy of the obtained thin films ranging between 3.1 eV and 4.6 eV. At room temperature, the electrical resistivity of the Ni(II)-2,2-bipyridine complexes thin films ranged between 0.46 × 105 Ω cm and 7.58 × 105 Ω cm. Thus, this study proves that these materials can be used as selective absorbers in many areas (organic solar cell, optical filters, etc.) owning to their effective semiconductor properties.