Spectroscopic characterization of Praseodymium doped Gallium Nitride powder prepared by a Na flux method
Spectroscopic characterization of Praseodymium doped Gallium Nitride powder prepared by a Na flux method
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DOI：
10.1016/j.jallcom.2008.11.029
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发表时间：
2009-12
影响因子：
6.2
通讯作者：
E. Brown;U. Hommerich;Takahiro Yamada;H. Yamane;J. Zavada
中科院分区：
文献类型：
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作者：
E. Brown;U. Hommerich;Takahiro Yamada;H. Yamane;J. Zavada
研究了Na助熔剂法制备的Pr3+掺杂GaN粉末的光致发光（PL）性能。在能隙上方和下方激发下，GaN:Pr 粉末表现出以 ~650nm 为中心的强烈红色发射线，对应于 Pr3+ 的 4f 内跃迁 3P0→3F2。此外，在~960、~1300和~1500-1700nm处从Pr3+的较低激发态观察到弱红外PL带。对红光发射的温度依赖性研究表明，在 10-300K 的温度范围内，在间隙上方激发下，积分 PL 强度降低了两倍。在间隙激发下没有观察到红色 Pr3+PL 的明显热猝灭。时间分辨发射研究表明，红色 PL 的衰减瞬态的特征是快速非指数衰减，随后是较慢衰减的指数分量。非指数衰减可归因于 Pr3+ 离子之间的交叉弛豫过程，而指数分量表明存在不受交叉弛豫发射猝灭影响的孤立 Pr3+ 中心。
The photoluminescence (PL) properties of Pr3+doped GaN powders prepared by a Na flux method were investigated. Under above- and below-gap excitation, GaN:Pr powders exhibited intense red emission lines centered at ∼650nm corresponding to the intra-4f transition3P0→3F2of Pr3+. In addition, weak infrared PL bands were observed from lower excited states of Pr3+at ∼960, ∼1300, and ∼1500–1700nm. A temperature dependent study of the red emission showed that the integrated PL intensity decreased by a factor of two under above-gap excitation for the temperature range 10–300K. No significant thermal quenching of the red Pr3+PL was observed under below-gap excitation. Time-resolved emission studies revealed that the decay transient of the red PL was characterized by a fast non-exponential decay followed by a slower decaying exponential component. The non-exponential decay can be attributed to cross-relaxation processes among Pr3+ions, whereas the exponential component suggests the existence of isolated Pr3+centers not affected by emission quenching through cross-relaxations.