论文标题
通过深色缺陷状态进行发光淬火：通过CE掺杂YAG中的氧气空位的重组途径
Luminescence quenching via deep defect states: A recombination pathway via oxygen vacancies in Ce-doped YAG
论文作者
论文摘要
通过非辐射重组通道进行发光淬火限制了光学材料（例如磷光器和闪烁体）的效率，因此对转换效率和设备寿命具有影响。在诸如CE掺杂的Yttrium铝石榴石（YAG：CE）之类的材料中，淬火表现出对温度和激活浓度的强烈依赖，从而限制了制造具有高工作温度的高强度白光发射二极管的能力。在这里，我们通过第一原理计算揭示了YAG：CE中有效的重组机制，该机制涉及氧空位，并引起热活化的浓度淬火。我们证明，该机制活跃的关键要求是具有强phonon耦合的局部状态。这些条件通常是针对固有缺陷的，例如宽带隙材料中的阴离子空位。因此，目前的发现与一系列的光学材料相关，并在整个热淬灭机制上发光。
Luminescence quenching via non-radiative recombination channels limits the efficiency of optical materials such as phosphors and scintillators and therefore has implications for conversion efficiency and device lifetimes. In materials such as Ce-doped yttrium aluminum garnet (YAG:Ce), quenching shows a strong dependence on both temperature and activator concentration, limiting the ability to fabricate high-intensity white-light emitting diodes with high operating temperatures. Here, we reveal by means of first-principles calculations an efficient recombination mechanism in YAG:Ce that involves oxygen vacancies and gives rise to thermally activated concentration quenching. We demonstrate that the key requirements for this mechanism to be active are localized states with strong electron-phonon coupling. These conditions are commonly found for intrinsic defects such as anion vacancies in wide band-gap materials. The present findings are therefore relevant to a broad class of optical materials and shine light on thermal quenching mechanisms in general.
