Near-field photoluminescence study of GaNAs alloy epilayer at room and cryogenic temperature
Near-field photoluminescence study of GaNAs alloy epilayer at room and cryogenic temperature
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GaNAs合金外延层室温和低温近场光致发光研究
DOI：
10.1063/1.1353815
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发表时间：
2001
影响因子：
4
通讯作者：
S. Takagishi
中科院分区：
文献类型：
--
作者：
K. Matsuda;T. Saiki;M. Takahashi;A. Moto;S. Takagishi
我们用近场扫描光学显微镜测量了GaAs(N∼0.8%)外延层的光学性质的空间分布，以研究室温和低温下的载流子复合机制。在室温下没有观察到宏观和近场光致发光(PL)光谱的差异。在低温下，我们发现了光学性质的空间不均匀性和近场光致发光光谱的尖锐特征。这些发现表明，由于组分的波动，在低温下，主要的发射机制从室温下的离域载流子的复合转变为局域电势极小值的局域载流子(激子)的复合。
We have measured the spatial distribution of the optical properties of a GaNAs (N∼0.8%) epilayer to investigate the carrier recombination mechanism at both room temperature and cryogenic temperature using a near-field scanning optical microscope. A difference between the macro and near-field photoluminescence (PL) spectra at room temperature was not observed. At low temperature, we found spatial inhomogeneity of the optical properties and sharp features in the near-field PL spectrum. These findings indicate that the dominant emission mechanism changes from recombination of delocalized carriers at room temperature to recombination of localized carriers (excitons) trapped in the local potential minimum due to compositional fluctuation at low temperature.