Electronic Structures of the Doped Cesium Niobate Cs$_2$Nb$_4$O$_{11}$

POSTER

Abstract

Samples of the photocatalyst cesium niobate (Cs$_2$Nb$_4$O$_{11}$) have been prepared with various amounts tantalum and sulfur doped onto the niobium and oxygen sites, respectively. Tantalum doping was effected by solid-state reactions at very high temperatures. Sulfur substitution was effected by passing gaseous carbon disulfide over pure or tantalum-doped samples at elevated temperatures. The amount of sulfur substitution was controlled by varying the time and temperature of the reaction, with higher temperatures and longer reaction times affording greater substitution. Band-gap values varied in accordance with composition are compared with the density functional theory calculations and experimental techniques such as the optical reflectance spectroscopy and spectroscopic ellipsometry, and the agreement is impressive.

Authors

  • Jianjun Liu

    • Department of Chemistry, University of Nebraska Omaha, Lincoln, NE 68182

  • Robert Smith

    • Department of Chemistry, University of Nebraska Omaha, Lincoln, NE 68182

  • Lu Wang

    • Department of Physics, University of Nebraska at Omaha, Omaha, NE 68182

  • Wai-Ning Mei

    • Department of Physics, University of Nebraska at Omaha, Omaha, NE 68182

  • Renat Sabirianov

    • Department of Physics, University of Nebraska at Omaha, Omaha, NE 68182

  • Hsin-Yi Hsu

    • Department of Physics, National Taiwan Normal University, Taipei 11677, Taiwan

  • Hsiang-Lin Liu

    • Department of Physics, National Taiwan Normal University, Taipei 11677, Taiwan