Two-photon excitation spectroscopy of coupled asymmetric GaN/AlGaN quantum discs
Two-photon excitation spectroscopy of coupled asymmetric GaN/AlGaN quantum discs
复制标题
耦合不对称 GaN/AlGaN 量子盘的双光子激发光谱
DOI：
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发表时间：
2006
期刊：
影响因子：
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通讯作者：
T. Kang
中科院分区：
文献类型：
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作者：
K. H. Lee;S. Birner;J. H. Na;R. A. Taylor;S. Yi;Y. S. Park;C. M. Park;T. Kang
通过使用双光子激发光谱，我们利用增加的空间分辨率来对GaN量子盘的几个离散堆叠进行时间积分和时间分辨的光致发光测量。该堆叠结构由耦合的非对称GaN量子盘与嵌入式AlGaN势垒组成，其生长在GaN纳米柱的尖端。我们观察到，随着光激发功率的增加，由于自由载流子屏蔽，载流子寿命降低，由于较小量子盘的载流子隧穿，在较大量子盘中的屏蔽效应增强。
By using two-photon excitation spectroscopy we take advantage of the increased spatial resolution to perform time-integrated and time-resolved photoluminescence measurements on several discrete stacks of GaN quantum discs. The stack structure consisted of coupled asymmetric GaN quantum discs with embedded AlGaN barriers, which were grown at the tip of a GaN nanocolumn. We observed that with increasing optical excitation power the carrier lifetime decreased due to free-carrier screening, with an enhancement of the screening effect in the larger quantum disc due to carrier tunnelling from the smaller quantum disc.