Photoreflectance study of the temperature dependence of excitonic transitions in dilute GaAsN alloys
Photoreflectance study of the temperature dependence of excitonic transitions in dilute GaAsN alloys
复制标题
稀 GaAsN 合金中激子跃迁温度依赖性的光反射研究
DOI：
10.1002/pssa.201300462
复制
发表时间：
2014
期刊：
影响因子：
--
通讯作者：
and H. Yaguchi
中科院分区：
文献类型：
--
作者：
W. Okubo;S. Yagi;Y. Hijikata;K. Onabe;and H. Yaguchi
本文利用光反射谱研究了稀GaAsN合金的光学跃迁随温度的变化。在PR光谱中清楚地观察到离域态跃迁，而在光致发光光谱中出现由于等电子中心引起的几条局域态发射线。光致发光激发谱中的激子跃迁能量与光致共振谱中的光跃迁能量一致，说明光致共振谱中的光跃迁是激子跃迁。我们使用玻色-爱因斯坦统计表达式分析了激子跃迁能量的温度依赖性，发现即使是稀合金也遵循与氮浓度较高的GaAsN合金相同的趋势。本文从N原子随机分布的角度讨论了稀GaAsN合金中局域态和离域态的共存。
We have studied the temperature dependence of optical transitions in dilute GaAsN alloys using photoreflectance (PR). A delocalized‐state transition is clearly observed in PR spectra while several localized‐state emission lines due to isoelectronic centers appear in photoluminescence spectra. The energy of optical transitions observed in PR spectra is in agreement with the excitonic transition energy in photoluminescence excitation spectra, clearly showing that the optical transitions in PR spectra are excitonic transitions. We analyzed the temperature dependence of the excitonic transition energies using the Bose–Einstein statistical expression, and found that even dilute alloys follow the same trend as GaAsN alloys with higher nitrogen concentrations. We discuss the coexistence of localized and delocalized states in dilute GaAsN alloys in terms of the random distribution of N atoms.