Xuezhuan Yi

Composite phase ceramic phosphor of Al2O3-Ce:YAG for high efficiency light emitting

We present our achievement which is a ceramic plate phosphorable to produce white light when directly combined with commercially available blue light emitting diodes. The ceramic phase structure is that the Al₂O₃ particle is uniformly distributed in the Ce:YAG matrix. The Al₂O₃-Ce:YAG ceramic phosphor has a better luminous efficacy than the transparent Ce:YAG ceramic phosphor under the same test condition. The Al₂O₃ particle plays an important role in promoting the luminous efficacy. The Al₂O₃ particle changes the propagation of the light in ceramic, and it reduces the total internal reflection. That is why the composite phase ceramic phosphor improves extraction efficiency of light.

Fabrication of transparent Tb3Ga5O12 ceramic

Tb3Ga50I2 (TGG) is an excellent material for magneto-optical applications, and is the key component in Faraday isolators (FIs). The preparation process of transparent TGG ceramics is experimentally studied. The optical quality and the microstructure of the samples are investigated. The results show that the transmittance of the sample sintered at 1550°C is close to 72% in the region of 500-1500 nm. The Verdet constant at 632.8 nm measured at room temperature is - 125.01 rad T-I m-I, which is almost the same as that of a single crystal.

Comparison of Ce3+/Yb3+ with Er3+/Yb3+ down-conversion pairs in YAG host for improving the efficiency of the crystalline silicon solar cells

Re3+, Yb3+ co-doped (Re0.005YbxY(0.995-x))3Al5O12 [Re = Ce, Er, x = 0, 0.02, 0.05, 0.1, and 0.2] transparent ceramics are synthesized by the solid state reaction and vacuum sintering as the down-conversion (DC) materials. The photoluminescence excitation and the photoluminescence spectra demonstrate the near-infrared quantum cutting (QC) and the energy transfer (ET) from Re3+ to Yb3+ in both of these series of samples. The comparison of the near-infrared QC spectra of the two series of samples shows that the Ce3+, Yb3+ co-doped Y3Al5O12 transparent ceramic samples have much higher intensity of the emission spectra in the near-infrared region, and higher ET efficiency than the Er3+, Yb3+ co-doped ones. So, the Ce3+, Yb3+ DC ion pair is a better choice to improve the efficiency of the crystalline silicon-based solar cells.