Thermal sensors based on ytterbium-erbium doped nano-glassceramics
Lead-fluoride nano-glassceramics doped with ytterbium and erbium have been developed and synthesized. The influence of heating on the green up-conversion luminescence of erbium has been experimentally investigated. Nano-glassceramics are promising candidates for temperature sensors.
Site selective study of Eu3+-doped transparent oxyfluoride glass ceramics
Optical properties of Eu3+ ions in oxyfluoride glasses and glass ceramics doped with two different concentrations, 0.1 and 1 mol %, have been analyzed and compared with previous results for higher concentrated samples, 2.5 mol %. The Eu3+ ions in the 0.1 mol % doped glass ceramics are diluted into like crystalline environments with higher symmetry and lower coupled phonon energy than in the precursor glasses; meanwhile in the 1 mol % doped glass ceramics the presence of EuF3 clusters has been observed in addition to diluted ions. Fluorescence line narrowing measurements indicate the presence of two main fluoride site distributions for the diluted Eu3+ ions in both glass ceramics.
Photoreflectance characterization of vanadium-doped GaAs layers grown by metalorganic vapor phase epitaxy
Abstract We characterized the vanadium-doped (GaAs:V) layers grown on GaAs substrate by metalorganic vapor phase epitaxy. The conductivity of the samples is checked by the Hall effect measurements, and it is n type with electrons concentration ranging from 2×10 13 to 2×10 17  cm −3 . We used the photoreflectance technique (PR) to study the effect of vanadium doping on the optical properties of GaAs. Our experimental results show that the built-in electric field F and the broadening parameter Γ 0 increase with V-doping concentration. Furthermore, the temperature dependence of the built-in electric field and the broadening parameter of GaAs:V samples have been investigated by PR. It has been observed that these parameters increase with increasing temperature. The decrease of the built-in electric field with decreasing temperature is due to the photovoltage effect.We characterized the vanadium-doped GaAs (GaAs:V) layers grown on GaAs substrate by metalorganic vapor phase epitaxy.