H.M.N. Bandara

Improved performance of dye-sensitized solar cells using a diethyldithiocarbamate-modified TiO 2 surface

The surface modification of a TiO2 electrode with diethyldithiocarbamate (DEDTC) in dye-sensitized solar cells (DSSCs) was studied. Results fromX-ray photoelectron spectroscopy (XPS) indicate that over half of the sulfur atoms become positively charged after the DEDTC treatment of the TiO2 surface. DSSCs were fabricated with TiO2 electrodes modified by adsorbing DEDTC using a simple dip-coating process. The conversion efficiency of the DSSCs has been optimized to 6.6% through the enhancement of the short-circuit current density (JSC = 12.74 mA/cm2). This is substantially higher compared to the efficiency of 5.9% (JSC = 11.26 mA/cm2) for the DSSCs made with untreated TiO2 electrodes.

Nanocomposites of poly(3,4-ethylenedioxythiophene) and montmorillonite clay: synthesis and characterization:

Poly(3,4-ethylenedioxythiophene) (PEDOT)/montmorillonite (MMT) clay nanocomposites were prepared for the first time, by exchanging exchangeable cations in the MMT interlayer with Ce(IV) followed by insertion of ethylenedioxythiophene monomer to result in spontaneous polymerization to give PEDOT—Ce(III)—MMT nanocomposites. The nanocomposites thus prepared were characterized by electrochemical methods, elemental analysis, X-ray diffraction (XRD), Fourier transform infrared spectroscopy, thermogravimetric analysis, differential scanning calorimetry, and in situ conductivity measurements. Cyclic voltammograms of PEDOT—Ce(III)—MMT in 0.1 M H2SO 4 on glassy carbon electrode shows characteristics redox behavior that appear in Ce(IV)/Ce(III) and in Ce(IV)—MMTunder identical conditions together with typical electrochemical behavior of PEDOT. Further XRD results confirm that PEDOT has been intercalated within the MMT interlayer and the electrochemical impedance spectroscopy analysis implies that the organics are in their electronically conducting polymer form with significant electronic conductivity. As such, these nanocomposites may find applications in rechargeable batteries and photovoltaic devices as electrode materials and as antistatic coatings for electrical appliances.

Ethylene Glycol Assisted Synthesis of Fluorine Doped Tin Oxide Nanorods Using Improved Spray Pyrolysis Deposition Method

Fluorine-doped tin oxide nanorod transparent thin films were fabricated with SnCl45H2O, NH4F, and ethylene glycol (EG) using an improved spray pyrolysis deposition technique. The fabricated nanorods showed a low resistance of 15.3 Ω/sq and a good transparency of 70.8%. The nanorods have a higher surface area than the conventionally used thin films.

Ionic conductivity of cuprous sulphate

Abstract Ionic conductivity of cuprous sulphate has been measured using complex impedance technique. The material is found to be a solid ionic conductor with ionic conductivity of 5.6 × 10 −4 (ohm cm) −1 at 27°C and neglegible electronic conductivity. The temperature dependence of the conductivity has been studied from 27 to 60°C, and the activation energy is found to be 0.31 eV.