(CH2)6N4 is also known as a weak base and pH buffer , being considered a steady source for slow release of HO− ions. All these (CH2)6N4 characteristics influence the nucleation and the growth rates of different ZnO crystal facets, processes responsible for the overall structure and morphology. We investigate the dependence of the ZnO morphology for different reaction
SCH772984 mouse parameters varying the precursors’ concentration (both reactants with 0.05, 0.1, Epacadostat research buy or 0.2 mM, the Zn(NO3)2/(CH2)6N4 molar ratio was always 1:1) and the deposition time (3 and 6 h). Thus, the synthesized samples were labeled as follows: a (0.05 mM, 3 h), b (0.1 mM, 3 h), c (0.2 mM, 3 h), d (0.05 mM, 6 h), e (0.1 mM, 6 h), and f (0.2 mM, 6 h). The crystalline phase of the samples was identified by X-ray diffraction (XRD) on a Bruker AXS D8 Advance instrument (Karlsruhe, Germany) with Cu Kα radiation (λ = 0.154 nm). The source was operated at 40 kV and 40
mA and the Kα radiation was removed using a nickel filter. The optical properties of the ZnO GDC-0994 samples were investigated by measuring the total reflection spectra using a PerkinElmer Lambda 45 UV-VIS spectrophotometer (Waltham, MA, USA) equipped with an integrating sphere. The photoluminescence (PL) measurements were performed at 350 nm excitation wavelength using FL 920 Edinburgh Instruments spectrometer (Livingston, UK) with a 450-W Xe lamp excitation and double monochromators on both excitation and emission. All PL spectra were recorded in the same experimental conditions (excitation wavelength = 350 nm, step, dwell time, slits). The sample morphologies were evaluated using a Zeiss Evo 50 XVP scanning electron microscope (SEM, Oberkochen, Germany). Electrical measurements were carried out
using a Keithley 4200 SCS (Cleveland, OH, USA) and a Cascade Microtech MPS 150 probe station (Thiendorf, Germany). The current-voltage characteristics were obtained by the conventional MycoClean Mycoplasma Removal Kit two-probe method on the samples exposed at different times and at room temperature to ammonia vapors (an area of about 3 mm2 in size contains the patterned metallic stripes and millimeter-sized electrodes). The wetting properties of the ZnO samples were determined by measuring the static contact angle (CA) with a Drop Shape Analysis System, model DSA100 from Kruss GmbH (Hamburg, Germany) . The sample was placed on a plane stage, under the tip of a water-dispensing disposable blunt-end stainless steel needle with an outer diameter of 0.5 mm. The needle was attached to a syringe pump controlled by a PC for delivery of the water droplet to the test surface. Drop volume was gradually increased until the drop adhered to the surface this being achieved when the volume reached approximately 3 to 4 μl. All the CA measurements were carried out in the static regime at room temperature.