CuO/CuO bilayers were fabricated by electrodeposition of the CuO layer in a copper(II)-ammonia complex aqueous solution, followed by photoelectrochemical deposition of the CuO layer at potentials ranging from -0.3 to -1.0 V referenced to a Ag/AgCl electrode in a copper(II)-lactate complex aqueous solution under light irradiation, and the effects of varied potentials of the photoelectrochemical CuO depositions and post-heating conditions on their structural, optical, and photovoltaic characteristics were investigated with X-ray diffraction, field emission-scanning electron microscopy, optical absorption measurements, and external quantum efficiency (EQE) measurements with and without applied bias voltage.
View Article and Find Full Text PDFThe quality of a semiconductor, which strongly affects its performance, can be estimated by its photoluminescence, which closely relates to the defect and impurity energy levels. In light of this, it is necessary to have a measurement method for photoluminescence properties with spatial resolution at the sub-micron or nanoscale. In this study, a mapping method for local photoluminescence properties was developed using a focused synchrotron radiation X-ray beam to evaluate localized photoluminescence in bi-layered semiconductors.
View Article and Find Full Text PDFStacking layered metal hydroxide films parallel to a substrate is challenging. Here, we demonstrate a simple and rapid electrodeposition method for stacking magnesium hydroxide layered films. Room-temperature cathodic electrolysis (40 mA cm) in a Mg(NO) aqueous solution induces the deposition of ⟨001⟩-oriented Mg(OH) layered films stacked parallel to the substrate at the deposition rate of ∼2 μm min.
View Article and Find Full Text PDFp-CuO with a band gap energy of 1.5 eV, p-CuO with a band gap energy of 2.05 eV, and their bilayers were prepared by controlling the potential of anodic and cathodic polarization in a copper(II)-tartrate complex aqueous solution containing copper(II) sulfate hydrate and tartaric acid in the dark and under light irradiation.
View Article and Find Full Text PDFThermal decomposition of layered zinc hydroxides (LZHs) is a simple and convenient way to achieve porous ZnO nanostructures. The type of anion contained in an LZH determines the fundamental characteristics of the LZH and thus affects the formation process of the resulting porous ZnO. Here we report a comparative study on the crystal orientation relationship between LZH precursors and the corresponding porous ZnO products by using well-faceted and highly oriented LZH crystals with three different anions, i.
View Article and Find Full Text PDFThe standard technique to separately and simultaneously determine the carrier concentration per unit volume (N, cm ) and the mobility (μ) of doped inorganic single crystals is to measure the Hall effect. However, this technique has not been reported for bulk-doped organic single crystals. Here, the Hall effect in bulk-doped single-crystal organic semiconductors is measured.
View Article and Find Full Text PDFCl-doped ZnO-nanowire (Cl:ZnO-nws)/Cu2O photovoltaic devices were prepared by electrodeposition in aqueous solutions, and the effects of the insertion of the highly resistive ZnO (i-ZnO) layer has been demonstrated by an improvement of the photovoltaic performance. The Cl:ZnO-nws and i-ZnO layer were prepared by electrodeposition in a zinc chloride aqueous solution with saturated molecular oxygen and simple zinc nitrate aqueous solution, respectively. The i-ZnO layer was directly deposited on the Cl:ZnO-nws and suppressed the electrodeposition of the Cu2O layer on the Cl:ZnO-nws.
View Article and Find Full Text PDFACS Appl Mater Interfaces
October 2013
We report a hybrid photovoltaic device composed of a 3.3 eV bandgap zinc oxide (ZnO) semiconductor and metal-free phthalocyanine layers and the effects of the insertion of the highly resistive ZnO buffer layer on the electrical characteristics of the rectification feature and photovoltaic performance. The hybrid photovoltaic devices have been constructed by electrodeposition of the 300 nm thick ZnO layer in a simple zinc nitrate aqueous solution followed by vacuum evaporation of 50-400 nm thick-phthalocyanine layers.
View Article and Find Full Text PDFACS Appl Mater Interfaces
July 2012
We report on a hybrid diode composed of a 2.1 eV bandgap p-cupric oxide (Cu2O) semiconductor and fullerene (C60) layer with a face-centered cubic configuration. The hybrid diode has been constructed by electrodeposition of the 500 nm thick Cu2O layer in a basic aqueous solution containing a copper acetate hydrate and lactic acid followed by a vacuum evaporation of the 50 nm thick C60 layer at the evaporation rate from 0.
View Article and Find Full Text PDFCore/shell nanostructures of polystyrene (PS)/CeO2 have been prepared on conductive glass substrates by using a novel electrochemical route consisting of (i) the electrophoretic deposition of a PS sphere monolayer on the substrate and (ii) the following potentiostatic electrodeposition of CeO2 on the PS sphere template in Ce(NO3)3 aqueous solutions. The structural morphologies of the deposit changed drastically depending on the Ce(NO3)3 concentration; i.e.
View Article and Find Full Text PDFChem Commun (Camb)
March 2002
Highly (0001) oriented zinc oxide (ZnO) films of smooth layer type and hexagonal columns have been prepared on quartz glass substrates at temperature as low as 323 K by UV light assisted chemical deposition from an aqueous solution containing hydrated zinc nitrate and dimethylamine-borane (DMAB).
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