Carbon interstitial defects causing emission red shift in YAG:Ce phosphor:First-principles calculation

Yaling Zheng^1,2，Weidong Zhuang¹，Xianran Xing²，Ronghui Liu¹，Yanfeng Li¹，Yuanhong Liu¹，Yunsheng Hu¹，Xiaoxia Chen¹，Lei Chen¹，Xiaole Ma¹

1. National Engineering Research Center for Rare Earth Materials, General Research Institute for Nonferrous Metals, and Grirem Advanced Materials Co.,Ltd.2. Department of Physical Chemistry,University of Science & Technology Beijing

摘 要：Y₃ Al₅ O₁₂:Ce3+ is the most famous phosphor material due to its excellent photolumincent properties.Here,through first-principles calculation,the effect of carbon interstitial defects on Y₃ Al₅ O₁₂:Ce3+phosphor was investigated. It is found that the carbon interstitials tend to occupy the next-nearest sites of Ce³⁺ ion in Y₃ Al₅ O₁₂:Ce3+ lattice. Specially,these interstitial defects can shorten the Ce3+-O^2- bond length, leading to a larger crystal field splitting of 5 d orbital of the Ce³⁺ atom and bigger 5 d centroid shift.These two factors cause the emission spectrum of Y₃ Al₅ O₁₂（C）:Ce³⁺ red shift compared with that of Y₃ Al₅ O₁₂:Ce3+. Moreover, with our comparison experiment, we find that the Y₃ Al₅ O₁₂（C）:Ce3+ has an obvious red shift compared with that of Y₃ Al₅ O₁₂:Ce³⁺ system,which is in accord with our first principles calculation. Our work systematically investigates the impact of the carbon interstitial defect on Y₃ Al₅ O₁₂:Ce³⁺,and provides a new route to tune the emission spectrum in Y₃ Al₅ O₁₂:Ce³⁺.

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