Z. Serbetci

Photoluminescence and refractive index dispersion properties of ZnO nanofibers grown by sol–gel method

Zinc oxide thin film was grown on glass substrate using sol-gel spin coating method. The optical constants and dispersion energy parameters of the zinc oxide thin film were determined using optical characterization method. The optical band gap of the n-type ZnO semiconductor was found to be 3.24 eV. The refractive index dispersion of the ZnO obeys the single oscillator model. The dispersion energy and oscillator energy values of the ZnO film were found to be 13.74 eV and 6.61 eV, respectively. The real and imaginary parts of the dielectric constant of the ZnO film were determined. The photoluminescence spectra of the ZnO film indicate a peak around 401 nm (3.10 eV) due to the electron transition from the energy level of interstitial Zn to valance band and the another peak is observed around 530 nm (2.34 eV) which is attributed to the oxygen vacancies in ZnO.

Ruthenium(II) Complex Based Photodiode for Organic Electronic Applications

In this study, the electrical and photoresponse properties of a photovoltaic device with Ruthenium(II) complex interfacial thin film were investigated. Heteroleptic Ru(II) complex including bidentate and tridentate ligands thin film was coated on n-Si substrate by the spin coating technique. From current–voltage (I–V) measurements of an Au/Ru(II)/n-Si photodiode, it is observed that the reverse bias current under light is higher than that of the current in the dark. This indicates that the photodiode exhibits a photoconducting characteristic. The transient measurements such as photocurrent, photocapacitance and photoconductance were performed under various illumination conditions. These measurements indicate that the photodiode has a high photoresponsivity. The electrical parameters such as barrier height (Φb), ideality factor (n) and series resistance (Rs) of the photodiode were determined from the analysis of I–V characteristics. Moreover, the capacitance/conductance–voltage characteristics of the photodiode highly depend on both voltage and frequency. Results show that the heterojunction can be used for various optoelectronic applications.

Synthesis and Catalytic Activity of Semiconducting p-Cymene Ruthenium 1,3,4-Thiadiazole and 1,2,4-Triazole Complexes

The novel ruthenium(II) complexes containing 5-(pyridin-4-yl)-1,3,4-thiadiazol-2-amine(1) and 4-amino-5-(pyridin-4-yl)-4H-1,2,4-triazole-3-thiol (2) ligands were synthesized and characterized by UV-Vis, IR, NMR, and elemental analysis. The complexes have been employed as catalysts for the transfer hydrogenation of acetophenone in the presence of KOH using 2-propanol as a hydrogen source at 82°C. Moreover, the temperature dependence of conductivity of the complexes was determined in the temperature range of 303–373 K. The complex [Ru(1,2)(p-cymene)Cl2] exhibits the semiconducting behavior, as the conductivity of the samples is increased with the increase in temperature.