title: Determination of absolute quantum efficiency of X-ray nano phosphors by thin film photovoltaic cells.
abstract: The absolute optical power at 611 nm emitting from Eu doped Gd2O3 nano phosphors upon X-ray excitation from a microfocus X-ray source operated at 100 kV was measured with thin film photovoltaic cells (TFPCs), whose optical response was calibrated using an He-Ne laser at 632 nm. The same TFPCs were also used to determine the absorbed X-ray power by the nano phosphors. These measurements provided a convenient and inexpensive way to determine the absolute quantum efficiency of nano phosphors, normally a difficult task. The measured absolute X-ray-to-optical fluorescence efficiency of the nano phosphors annealed at 1100 °C was 3.2%. This is the first time such efficiency for Eu/Gd2O3 nano phosphors is determined, and the measured efficiency is a fraction of the theoretically predicted maximum efficiency of 10% reported in the literature.
authors.affiliation: Department of Chemistry, University of California-Davis , Davis, California 95616, United States.
authors.forename: R Andrew
authors.initials: RA
authors.lastname: Davidson
authors.forename: Chad
authors.initials: C
authors.lastname: Sugiyama
authors.forename: Ting
authors.initials: T
authors.lastname: Guo