Spectral and time-resolved photoluminescence studies of Eu-doped GaN
Spectral and time-resolved photoluminescence studies of Eu-doped GaN
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Eu 掺杂 GaN 的光谱和时间分辨光致发光研究
DOI：
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发表时间：
2003
期刊：
影响因子：
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通讯作者：
J. Zavada
中科院分区：
文献类型：
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作者：
E. Nyein;U. Hommerich;J. Heikenfeld;Dong‐Seon Lee;A. Steckl;J. Zavada
我们报告的光谱和时间分辨的光致发光（PL）的研究进行了固体源分子束外延制备的Eu掺杂GaN。在14 K和室温之间，采用能隙上激发，Eu 3+在622.3 nm（5D0→7F2跃迁）的主谱线的积分光致发光强度下降了近90%。使用带隙以下激发，在相同的温度范围内，该谱线的积分强度仅下降0.50%。此外，Eu3+的PL光谱和衰减动力学变化显着相比，上述间隙激发。这些结果表明存在不同的Eu 3+中心具有不同的光学性质。光致发光激发测量显示共振内4f吸收线的Eu 3+离子，以及一个宽的激发带中心在400 nm。这种宽的激发带与较高的4f内Eu3+能级重叠，为GaN中Eu3+离子的载流子介导激发提供了有效的途径。
We report on spectral and time-resolved photoluminescence (PL) studies performed on Eu-doped GaN prepared by solid-source molecular-beam epitaxy. Using above-gap excitation, the integrated PL intensity of the main Eu3+ line at 622.3 nm (5D0→7F2 transition) decreased by nearly 90% between 14 K and room temperature. Using below-gap excitation, the integrated intensity of this line decreased by only ∼50% for the same temperature range. In addition, the Eu3+ PL spectrum and decay dynamics changed significantly compared to above-gap excitation. These results suggest the existence of different Eu3+ centers with distinct optical properties. Photoluminescence excitation measurements revealed resonant intra-4f absorption lines of Eu3+ ions, as well as a broad excitation band centered at ∼400 nm. This broad excitation band overlaps higher lying intra-4f Eu3+ energy levels, providing an efficient pathway for carrier-mediated excitation of Eu3+ ions in GaN.