Thermal quenching of phosphor is an important challenge for its practical application in phosphor‐converted white light‐emitting diodes (pc‐WLEDs) and it usually becomes aggravated with the increase of activator concentration. Conversely, this work finds the thermal quenching of Eu²⁺ emission at 490 nm in Sr₄Al₁₄O₂₅:Eu²⁺ does not follow this in the temperature range of 300 to 480 K, and the rate of it is even slowed down as the concentration of Eu²⁺ increases. However, at the same time, the experiment on three heating‐cooling cycles of Sr₄Al₁₄O₂₅:Eu²⁺ reveals that the thermal degradation of Eu²⁺ emission becomes improved. Once Eu²⁺ ions are doped into Sr₄Al₁₄O₂₅, they will prefer substituting for the 10‐ and 7‐coordinated strontium sites Sr1 and Sr2, respectively. The emission centers Eu1 and Eu2, therefore, appear. The abnormal phenomenon is perhaps partly due to the enhanced energy transfer from the emission center Eu1 at 407 nm to the one Eu2 at 490 nm. It is also found interesting that the introduction of AlN can enhance the emission of Sr₄Al₁₄O₂₅:Eu²⁺ without leading to the deterioration of thermal degradation. In the end, a prototype of pc‐WLED was fabricated with Sr₄Al₁₄O₂₅:Eu²⁺ to demonstrate the application of white lighting. This work is not only beneficial to the understanding of the relationship between concentration and thermal quenching, but also conducive to the design of the heavily doped phosphor for WLEDs with better resistance to thermal quenching.

中文翻译：

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在近紫外激发白光LED中，Sr4Al14O25：Eu2 +中不寻常的浓度引起Eu2 +发射在490 nm处的抗热猝灭

荧光粉的热淬灭是其在荧光粉转换的白光发光二极管（pc-WLED）中的实际应用的一个重要挑战，通常随着活化剂浓度的增加而加剧。相反，这项工作发现在300至480 K的温度范围内，Sr ₄ Al ₁₄ O ₂₅中Eu ^2+的发射在490 nm处发生热淬灭：Eu ²⁺并未遵循此要求，并且其速率甚至减慢了随着Eu ²⁺浓度的增加。然而，同时，对Sr ₄ Al ₁₄ O ₂₅：Eu ^2+的三个加热-冷却循环进行了实验揭示了Eu ²⁺发射的热降解得到改善。将Eu ²⁺离子掺杂到Sr ₄ Al ₁₄ O _25中后，他们将更喜欢分别取代10和7配位的锶位点Sr1和Sr2。因此，出现发射中心Eu1和Eu2。异常现象可能部分是由于从407 nm发射中心Eu1到490 nm一个Eu2的能量转移增强所致。还发现有趣的是，引入AlN可以增强Sr ₄ Al ₁₄ O ₂₅：Eu ²⁺的排放。不会导致热降解的恶化。最后，用Sr ₄ Al ₁₄ O ₂₅：Eu ²⁺制造了pc-WLED原型，以演示白光的应用。这项工作不仅有利于了解浓度与热猝灭之间的关系，而且有助于设计用于WLED的重掺杂磷光体，具有更好的抗热猝灭性。