Quantum Efficiency Measurement of Single-Particle Phosphor by Proximity Method

In this study, a technique for measuring the quantum efficiency of single-particle phosphors was developed. For this purpose, a proximity measurement technique capable of measuring the photoluminescence of a single particle with a high signal-to-noise ratio was adopted. Single optical fibers were combined with a commercially available spectrofluorometer to directly measure the light distribution near the phosphor. The number of photons absorbed by the phosphor can be evaluated by focusing the Xe light down to 18 & mu;m, which is equivalent to the particle diameter. By eliminating the optical parts as much as possible and performing spectral sensitivity calibration over a wide wavelength range, an internal quantum efficiency evaluation similar to a powder measurement was established.