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Herein, we report thin films’ characterizations and photovoltaic properties of an organic semiconductor zinc phthalocyanine (ZnPc). To study the former, a 100 nm thick film of ZnPc is thermally deposited on quartz glass by using vacuum thermal evaporator at 1.5 × 10−6 mbar. Surface features of the ZnPc film are studied by using scanning electron microscope (SEM) with in situ energy dispersive x-ray spectroscopy (EDS) analysis and atomic force microscope (AFM) which reveal uniform film growth, grain sizes and shapes with slight random distribution of the grains. Ultraviolet-visible (UV-vis) and Fourier Transform Infrared (FTIR) spectroscopies are carried out of the ZnPc thin films to measure its optical bandgap (1.55 eV and 3.08 eV) as well as to study chemical composition and bond-dynamics. To explore photovoltaic properties of ZnPc, an Ag/ZnPc/PEDOT:PSS/ITO cell is fabricated by spin coating a 20 nm thick film of hole transport layer (HTL)—poly-(3,4-ethylenedioxythiophene) poly(styrene sulfonic acid) (PEDOT:PSS)—on indium tin oxide (ITO) substrate followed by thermal evaporation of a 100 nm layer of ZnPc and 50 nm silver (Ag) electrode. Current-voltage (I-V) properties of the fabricated device are measured in dark as well as under illumination at standard testing conditions (STC), i.e., 300 K, 100 mW/cm2 and 1.5 AM global by using solar simulator. The key device parameters such as ideality factor (n), barrier height ( ϕ b ), junction/interfacial resistance (Rs) and forward current rectification of the device are measured in the dark which exhibit the formation of depletion region. The Ag/ZnPc/PEDOT:PSS/ITO device demonstrates good photovoltaic characteristics by offering 0.48 fill factor (FF) and 1.28 ± 0.05% power conversion efficiency (PCE), η.

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Electrochemical behaviour of molybdenum electrodes in various aqueous and buffered solutions and their use in titrations T he open circuit potential of Mo electrodes has been followed as a function of time in H. A. EL SHAYEB various aqueous solutions until steady state values E st were obtained. T hese varied with the F. M. ABD EL WAHAB logarithm of the molar concentration C as E st =a+b log C. T he rate of oxide film thicken-E. A. ABD EL MEGUID ing was determined from the linear relationship between the open circuit potential of Mo E and the logarithm of immersion time t as E=a 1 +b 1 log t. A plot of the final steady state potential of Mo as a function of the pH of buVered solutions fits the linear relationship E st =a 2 −b 2pH. T he oxide film formed on Mo provides the opportunity to use the metalmetal oxide as an indicator electrode for potentiometric acid-base and precipitation titrations. In the case of redox titrations, the Mo electrode could not be used successfully on its own, but when coupled with platinum as a bimetallic pair electrode, excellent results were obtained when used as an indicator electrode for oxidation-reduction reactions.

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