Selecting Conversion Phosphors for White Light Emitting Diodes

Philippe F. Smet,*,zAnthony B. Parmentier, and Dirk Poelman

Journal of The Electrochemical Society, 158 (6) R37-R54 (2011)

[DOI: 10.1149/1.3568524]

在热淬灭中，发光强度和decay随温度的变化规律一致：In first order, the decay time of the luminescence is following a similar thermal behavior than the intensity quenching。

在热淬灭研究中，荧光粉的激发光谱和发射光谱随温度的变化都要研究：Preferably, also the emission and excitation spectra should be reported as a function of temperature.

温度升高，Eu2+和Ce3+的发光光谱变宽：Upon increasing temperature, the emission spectrum of Eu2+ and Ce3+ broadens due to the occupation of higher vibrational levels. In addition, changes in the peak emission position are possible.

掺杂浓度、吸收效率和量子效率的关系：In general, increasing the dopant concentration in a phosphor increases the absorption at the excitation wavelength. However, there exists a trade-off between the increasing absorption (and emission) and a decrease in the internal quantum efficiency due to concentration quenching. For application in LEDs, using a phosphor with a high external quantum efficiency allows to use a low amount of phosphor
material on the LED chip. This limits the absorption losses of the down-converted light.