Spectroscopic properties of tetragonal LiYbF_4 nanocrystals under high dense NIR excitation at vacuum condition were investigated. White, broad band emission covering whole visible part of the spectrum from LiYbF_4 na...Spectroscopic properties of tetragonal LiYbF_4 nanocrystals under high dense NIR excitation at vacuum condition were investigated. White, broad band emission covering whole visible part of the spectrum from LiYbF_4 nanocrystals was observed. Its intensity strongly depended on the excitation power, excitation wavelength and ambient pressure. Temperature of the nanocrystals under 975 nm excitation was determined as a function of excitation power. Strong photo-induced current was observed from LiYbF_4 pallet. The emission kinetic was analyzed. The mechanism of the anti-Stokes white emission was discussed in terms of the laser-induced charge transfer emission from Yb^（2＋） states.展开更多
Near-infrared emission of Yb3＋ and Bi3＋-co-doped GdVO4 vanadate phosphors obtained via the modified Pechini＇s method was reported. The phase purity and structure of samples were characterized by X-ray powder diN＇a...Near-infrared emission of Yb3＋ and Bi3＋-co-doped GdVO4 vanadate phosphors obtained via the modified Pechini＇s method was reported. The phase purity and structure of samples were characterized by X-ray powder diN＇action （XRD）, X-ray energy disper- sion spectroscopy （EDS）, scanning electron microscopy （SEM）, Raman and infrared （IR） spectroscopy. Photoluminescence emission （PL） and excitation （PLE） spectra were recorded and investigated in details. Results indicated that upon near-UV excitation （340 nm） in the （Bi3＋-V5＋） charge transfer state this phosphor had a strong broad band yellow-green emission （3Pi--ISo） of Bi3＋ ions and also NIR emission （2Fs/2-2Fv/2） of Yb3＋ ions in the range of 950-1050 nm, which matched well with the spectral response of the sili- con-based solar cells. The decreasing Bi3＋ emission with increasing Yb3＋ concentration proved the occurrence of energy transfer from Bi3＋ to Yb3＋ ions. Results demonstrated that Yb3＋ and Bi3＋-co-doped GdVO4 vanadate phosphors might act as a NIR down-conversion （DC） solar spectral converter to enhance the efficiency of the silicon-based solar cells.展开更多
基金supported by National Centre of Science(NCS)Project(Poland)(NCN-2012/06/A/ST5/00212)
文摘Spectroscopic properties of tetragonal LiYbF_4 nanocrystals under high dense NIR excitation at vacuum condition were investigated. White, broad band emission covering whole visible part of the spectrum from LiYbF_4 nanocrystals was observed. Its intensity strongly depended on the excitation power, excitation wavelength and ambient pressure. Temperature of the nanocrystals under 975 nm excitation was determined as a function of excitation power. Strong photo-induced current was observed from LiYbF_4 pallet. The emission kinetic was analyzed. The mechanism of the anti-Stokes white emission was discussed in terms of the laser-induced charge transfer emission from Yb^（2＋） states.
文摘Near-infrared emission of Yb3＋ and Bi3＋-co-doped GdVO4 vanadate phosphors obtained via the modified Pechini＇s method was reported. The phase purity and structure of samples were characterized by X-ray powder diN＇action （XRD）, X-ray energy disper- sion spectroscopy （EDS）, scanning electron microscopy （SEM）, Raman and infrared （IR） spectroscopy. Photoluminescence emission （PL） and excitation （PLE） spectra were recorded and investigated in details. Results indicated that upon near-UV excitation （340 nm） in the （Bi3＋-V5＋） charge transfer state this phosphor had a strong broad band yellow-green emission （3Pi--ISo） of Bi3＋ ions and also NIR emission （2Fs/2-2Fv/2） of Yb3＋ ions in the range of 950-1050 nm, which matched well with the spectral response of the sili- con-based solar cells. The decreasing Bi3＋ emission with increasing Yb3＋ concentration proved the occurrence of energy transfer from Bi3＋ to Yb3＋ ions. Results demonstrated that Yb3＋ and Bi3＋-co-doped GdVO4 vanadate phosphors might act as a NIR down-conversion （DC） solar spectral converter to enhance the efficiency of the silicon-based solar cells.
