Browsing by Author "Volkmann, U. G."

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    Intra-cavity laser-assisted solar-energy conversion
    (2023) Jimenez, I.; Wallentowitz, S.; Seifert, B.; Volkmann, U. G.; Diaz-droguett, D. E.; Cabrera, A. L.; Gence, L.
    It is shown how to efficiently convert solar into electrical energy, taking advantage of laser amplification and intracavity use of a low-efficiency converter. The latter may consist of a low-efficiency transparent photovoltaic cell or a thermoelectric cell integrated into a metallic laser-cavity mirror, constituting a minor intra-cavity loss for the laser operation. The overall power-conversion efficiency is derived and discussed for a variety of current solid-state laser materials. It is shown that power-conversion efficiencies comparable with commercial silicon photovoltaic cells are obtained with current laser materials. & COPY; 2023 Optica Publishing Group under the terms of the Optica Open Access
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    Structural, optoelectronic and photo-thermoelectric properties of crystalline alloy CuAlxFe1-xO2 delafossite oxide materials
    (2021) Wheatley, R. A.; Roble, M.; Gence, L.; Acuna, C.; Rojas-Aedo, R.; Hidalgo-Rojas, D.; Guzman-De La Cerda, D. E.; Vojkovic, S.; Seifert, B.; Wallentowitz, S.; Volkmann, U. G.; Diaz-Droguett, D. E.
    CuFeO2 and CuAlO2 are attractive candidate materials for solar energy harvesting applications such as photocatalysis and photovoltaics. This work describes the structural, optoelectronic, thermal and electric properties of alloyed CuAlxFe1-xO2 Delafossite material synthesized using solid-state sintering techniques. The alloyed samples of CuAlxFe1-xO2 Delafossite oxide consisted of substitution of Fe for Al ranging from x = 0.01 to x = 0.99. The inclusion of Al in low concentrations affects the crystallization rate during solid-state synthesis, dramatically changing the resultant sample morphologies. The addition of dilute amounts of Al also greatly improves the conductivity of the material to a maximum of 3.18 Scm(-1). The material absorption edge shows strong changes over the alloying range. The more highly conducting samples show a strong photoinduced thermoelectric response to Vis-NIR illumination. (C) 2020 Published by Elsevier B.V.