Complex behavior of biexcitons in GaN quantum dots due to a giant built-in polarization field
Complex behavior of biexcitons in GaN quantum dots due to a giant built-in polarization field
复制标题
由于巨大的内置极化场，GaN 量子点中双激子的复杂行为
DOI：
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发表时间：
2008
期刊：
影响因子：
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通讯作者：
N. Grandjean
中科院分区：
文献类型：
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作者：
D. Simeonov;A. Dussaigne;R. Butté;N. Grandjean
利用低温显微光致发光技术对分子束外延生长的单极性GaN/AlN量子点进行了深入的光谱研究。发光线宽低至700 μ eV，允许得到彻底的表征的量子点的电子性质。双激子发射观察到一个很宽的范围内的点尺寸。结果表明，结合能（E-XX（B））呈现两种区域。主要的一个是由点的高度通过量子限制斯塔克效应导致的变化E-XX（B）从+3 meV的最小的点到-11 meV的最大的点。具有相同高度但不同横向尺寸的点的相反符号的二次变化被证明。
In-depth optical spectroscopic studies of single polar GaN/AlN quantum dots (QDs) grown by molecular beam epitaxy are carried out by means of low-temperature microphotoluminescence. Luminescence linewidths as low as 700 mu eV are obtained allowing thorough characterization of the QD electronic properties. Biexciton emission is observed for a wide range of dot size. It is shown that the binding energy (E-XX(b)) exhibits two regimes. The main one is governed by the dot height through the quantum confined Stark effect leading to a variation of E-XX(b) from +3 meV for the smallest dots to -11 meV for the largest ones. A secondary variation of opposite sign is demonstrated for dots having the same height but different lateral size.