Na8CeSi6O18 and Its Ti-Doped Analogue Na8Ce0.73Ti0.27Si6O18 with Interesting Photovoltaic Properties
datasetposted on 2011-06-14, 00:00 authored by Xi Wang, Jiyang Li, Yide Han, Yi Li, Jihong Yu, Ruren Xu
Na8CeSi6O18 and Na8Ce0.73Ti0.27Si6O18 (denoted CeSiO-CJ11A and CeTiSiO-CJ11B, respectively) were the first successful examples of Ce4+ and Ce4+/Ti4+ mixed silicates synthesized under mild hydrothermal conditions at 503 K. Their isostructure is confirmed by the powder X-ray diffraction (XRD) analysis. The single-crystal XRD analysis of CeSiO-CJ11A reveals that its structure is comprised of [Si6O18]n12n– cyclosilicate anions that are linked via CeO6 octahedra, giving rise to a three-dimensional (3D) framework that contains 6-membered ring channels delimited by the SiO4 tetrahedra and CeO6 octahedra along the -direction. Charge neutrality is achieved by Na+ ions located in the channels. Interestingly, the surface photovoltage (SPV) and transient photovoltage (TPV) studies of CeSiTiO-CJ11B show that it exhibits n-type semiconductor characteristics and a slow recombination process.