Correlations between Crystallite/Particle Size and Photoluminescence Properties of Submicrometer Phosphors

Abstract

Correlations between crystallite/particle size and the luminescent characteristics of submicrometer phosphors were investigated. Spray pyrolyzed europium doped yttrium oxide (Y2O3:Eu3+) particles were selected as a model material. Crystallite size and the particle size were controlled independently. The morphology and crystallite structure were characterized by field-emission scanning electron microscopy, high-resolution transmission electron microscopy, X-ray diffraction, and selected area electron diffraction. Photoluminescence (PL) properties were examined by spectrofluorophotometry and an absolute PL quantum efficiency (QE) measurement system. Chemical analyses and elemental mapping were conducted by Fourier transform infrared spectrophotometry and STEM equipped with energy dispersive spectroscopy, respectively. The results revealed that the PL properties were strongly dependent on crystallite size, particle size, surface chemistry, and the distribution of europium inside the phosphor particles. The PL intensities and QE increased with increasing crystallite size and particle size. The effect of crystallite size on PL properties played a more important role than that of particle size.

Crystallinity and morphological evolution of hydrothermally synthesized potassium manganese oxide nanowires

“…Increasing the stoichiometric portion of potassium precursors clearly increases the average nanowire diameter though such effect is not as apparent in terms of reaction temperature. It has been suggested that smaller crystal size is generally obtained at lower temperature [15] and this seems to be the case in our study. In addition, a higher temperature is preferable for the anisotropic growth of crystal, and results in a product with higher aspect ratios [15].…”

“…It has been suggested that smaller crystal size is generally obtained at lower temperature [15] and this seems to be the case in our study. In addition, a higher temperature is preferable for the anisotropic growth of crystal, and results in a product with higher aspect ratios [15].…”

Facile Synthesis of New Full‐Color‐Emitting BCNO Phosphors with High Quantum Efficiency

“…The emission peak of the sample prepared at 800 8C has a relatively higher intensity as compared to the sample prepared at 700 8C, which is not unexpected since photoluminescent materials prepared at higher temperatures generally exhibit higher PL intensities because of increased crystallinity. [12][13][14] However, the sample prepared at 900 8C shows the lowest PL intensity of this set of samples, and the PL spectra measured for this sample is very different from that of samples prepared at 700 and 800 8C. A possible explanation for this phenomenon is that the carbon content in the sample evaporates at 900 8C, thus significantly changing the composition of the sample.…”

Sub-second laser heating of thermal impulse sensors

“…While the Stark splitting of the energy levels depends on the specific lanthanide ion and its site symmetry, the fluorescence intensities vary with the degree of crystallinity of the host matrix and site symmetry. [14] All spectra are normalized to the Ho 3+ reference peak (Figure 2c). It is seen that the shape of this reference peak is generally unaffected by temperature.…”