The Experts below are selected from a list of 126 Experts worldwide ranked by ideXlab platform

Jiamei Cheng - One of the best experts on this subject based on the ideXlab platform.

  • controlled in situ fabrication of ag2o ago thin films by a dry chemical route at room temperature for hybrid solar cells
    Dalton Transactions, 2014
    Co-Authors: Jiamei Cheng, Zhi Zheng
    Abstract:

    Silver Oxides (Ag2O and AgO) have attracted increasing attention as potential solar cell materials for photovoltaic devices due to their ideal bandgap and non-toxicity. In order to eliminate the complicated synthesis and harsh reaction conditions (e.g. high temperature, high vacuum, high energy input, electron beam instrumentation) required by most synthetic strategies, we developed a very facile dry chemical approach to directly prepare AgxO species on the ITO substrate by taking advantage of a UV-O3 surrounding in a controlled way. We systematically investigated the effects of relative humidity, reaction temperature, and the Silver deposition technique on the formation of Silver oxide (AgO or Ag2O) thin films. A possible synthetic mechanism for the formation of AgO and Ag2O is proposed. More importantly, we have designed and successfully fabricated novel inorganic hybrid Ag2O/Bi2O3 heterojunction thin films for the first time which exhibit significantly improved photocurrent compared with pure Bi2O3 films.

Zhi Zheng - One of the best experts on this subject based on the ideXlab platform.

  • controlled in situ fabrication of ag2o ago thin films by a dry chemical route at room temperature for hybrid solar cells
    Dalton Transactions, 2014
    Co-Authors: Jiamei Cheng, Zhi Zheng
    Abstract:

    Silver Oxides (Ag2O and AgO) have attracted increasing attention as potential solar cell materials for photovoltaic devices due to their ideal bandgap and non-toxicity. In order to eliminate the complicated synthesis and harsh reaction conditions (e.g. high temperature, high vacuum, high energy input, electron beam instrumentation) required by most synthetic strategies, we developed a very facile dry chemical approach to directly prepare AgxO species on the ITO substrate by taking advantage of a UV-O3 surrounding in a controlled way. We systematically investigated the effects of relative humidity, reaction temperature, and the Silver deposition technique on the formation of Silver oxide (AgO or Ag2O) thin films. A possible synthetic mechanism for the formation of AgO and Ag2O is proposed. More importantly, we have designed and successfully fabricated novel inorganic hybrid Ag2O/Bi2O3 heterojunction thin films for the first time which exhibit significantly improved photocurrent compared with pure Bi2O3 films.

Nathaniel Tsendzughul - One of the best experts on this subject based on the ideXlab platform.

  • Surface characteristics of Silver oxide thin film electrodes for supercapacitor applications
    Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2017
    Co-Authors: Mojtaba Mirzaeian, A. A. Ogwu, Hassan Fathinejad Jirandehi, Saule Aidarova, Zhanar Ospanova, Nathaniel Tsendzughul
    Abstract:

    Abstract In this paper the preparation of nano-structured Silver oxide thin films with different oxidation states with promise as electrode materials for supercapacitors by reactive magnetron sputtering is investigated. The chemical, structural, surface morphological dependence of the films on oxygen gas flow rate and deposition power were examined by scanning electron microscope (SEM), X-ray diffraction (XRD) and energy dispersive X-ray (EDX). The average thickness of the films was controlled in the range of ≈50–330 nm. The XRD spectra of the films indicated the formation of bi-phase films comprised of Silver and Silver Oxides with different oxidation states. The wettability of the films in contact with different probing liquids was investigated by measuring the contact angles using a goniometer. It was shown that the Silver oxide films are relatively hydrophilic and increasing oxygen flow rate increases the wettability of the films toward water as a result of an increase in the oxidation state of the films and consequently clustering of electrons in polar molecules of water around the Oxides at higher oxidation states. This is further confirmed by the analysis of the surface energy measurements.

André Lefort - One of the best experts on this subject based on the ideXlab platform.

  • Work function measurements of contact materials for industrial use
    Journal of Applied Physics, 1998
    Co-Authors: Mohammed Akbi, André Lefort
    Abstract:

    The nature of the contact material is important for the characteristics of electric arcs and particularly for the electronic emission. Work functions of new industrial materials made with Silver alloys and Silver oxide alloys are not known at present. An experimental set-up is described which allows work function measurements from room temperature up to 700 K. The Fowler method was used for the measurement of the work function by the photoelectric effect. As a first application of the experimental device, work functions of metals (Ag, Cu, Ni, Sn and Zn) were determined. Furthermore, the influence of industrial surface treatment such as the application of electric arcs and repeated mechanical shocks on the Ag contact work surface was studied by SEM to observe their effect on electron work function. Breaking arcs in air cause a remarkable increase in the work function of the Silver contact material by progressive formation of Silver Oxides.

Martin Jansen - One of the best experts on this subject based on the ideXlab platform.

  • 109Ag chemical shifts of different Silver oxidation states in binary and ternary Silver Oxides
    Solid State Sciences, 2005
    Co-Authors: Leo Van Wüllen, Sascha Vensky, Wilfried Hoffbauer, Martin Jansen
    Abstract:

    Abstract Here we present 109Ag solid state magic angle spinning (MAS) NMR spectra for different Silver Oxides, binary as well as ternary. It is shown that the chemical shift of Silver nuclei is strongly dependent on the Silver oxidation state in these compounds and can thus serve as means to identify the Silver oxidation state in new materials.

  • electronic structure of Silver Oxides investigated by agl xanes spectroscopy
    Zeitschrift für anorganische und allgemeine Chemie, 1999
    Co-Authors: Peter Behrens, Stefanie Asmann, Uta Bilow, Christoph Linke, Martin Jansen
    Abstract:

    The chemistry of binary and multinary Silver Oxides spans from subvalent species (with a mean oxidation number for Ag smaller than + 1) to compounds with Ag in high oxidation states as + 2 and + 3. We have investigated a range of Silver Oxides, including the binary compounds Ag2O, AgO, Ag3O4 and Ag2O3 as well as subvalent ternary Oxides, by AgL3 and AgL1 XANES spectroscopy. The different valence states of Silver are clearly reflected in AgL3 and AgL1 XANES spectra. The method thus allows the determination of average oxidation numbers. In addition, the degree of electronic interaction (localized or delocalized electronic states) in Silver-oxygen compounds can be estimated on the basis of AgL3 XANES spectra. Untersuchung der elektronischen Struktur von Silberoxiden mit der AgL-XANES-Spektroskopie Die Chemie binarer und multinarer Silberoxide reicht von subvalenten Spezies (mit einer mittleren Oxidationsstufe von Ag, die kleiner als + 1 ist) bis zu Verbindungen mit Ag in hoheren Oxidationsstufen wie + 2 und + 3. Wir haben eine Reihe von Silberoxiden mit der AgL3- und der AgL1-XANES-Spektroskopie untersucht, darunter die binaren Oxide Ag2O, AgO, Ag3O4 und Ag2O3 wie auch subvalente ternare Oxide. Die unterschiedlichen Valenzzustande des Silbers spiegeln sich deutlich in den AgL3- und AgL1-XANES-Spektren wider. Diese Methode erlaubt somit die Bestimmung von mittleren Oxidationszahlen. Zusatzlich kann auch das Ausmas der elektronischen Wechselwirkung (lokalisierte oder delokalisierte elektronische Zustande) in Silber–Sauerstoff-Verbindungen mit Hilfe von AgL3-XANES-Spektren abgeschatzt werden.

  • subvalent ternary Silver Oxides synthesis structural characterization and physical properties of pentaSilver orthosilicate ag5sio4
    Inorganic Chemistry, 1994
    Co-Authors: Christoph Linke, Martin Jansen
    Abstract:

    Single crystals of Ag 5 SiO 4 have been obtained by hydrothermal reaction of Ag powder with amorphous SiO 2 under high oxygen pressure. The crystal structure was explored by single-crystal X-ray diffraction. Ag 5 SiO 4 crystallizes with ouhorhombic symmetry in space group Pnnm (No. 58) with a=9.856(1) A, b=9.108(1) A, c=6.271(1) A and 4 formula units per cell. The crystal structure of Ag 5 SiO 4 consists of Ag 6 clusters along with isolated Ag + and tetrahedral SiO 4 4- ions. The physical and structural properties suggest a formulation as [Ag 6 ] 4+ (Ag + ) 4 (SiO 4 4- ) 2