Optical properties of excitons in ZnO-based quantum well heterostructures
Optical properties of excitons in ZnO-based quantum well heterostructures
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DOI：
10.1088/0268-1242/20/4/010
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发表时间：
2005-04-01
影响因子：
1.9
通讯作者：
Koinuma, H
中科院分区：
文献类型：
--
作者：
Makino, T;Segawa, Y;Koinuma, H
最近，II-VI-氧化物领域的发展令人瞩目。已经使用各种外延方法来生长外延ZnO层。激光分子束外延（激光MBE）不仅可以生长外延层，还可以生长质量足够好的多量子阱（MQW）。我们主要讨论ZnO基MQW异质结构中激子光学性质的实验方面。对这些 MQW 中光吸收和光致发光的系统温度依赖性研究被用来评估主要激子特性的阱宽依赖性和成分依赖性。基于这些数据，讨论了激子的局域化、激子-声子相互作用的影响和量子限制斯塔克效应。稠密激子系统的光谱主要由激子和双激子之间的相互作用过程决定。高密度激子效应在 ZnO MQW 的室温受激发射观察中发挥着重要作用。由于量子限制效应，激子和双激子的结合能从体值增强。
Recently the developments in the field of II-VI-oxides have been spectacular. Various epitaxial methods have been used to grow epitaxial ZnO layers. Not only epilayers but also sufficiently good-quality multiple quantum wells (MQWs) have been grown by laser molecular-beam epitaxy (laser-MBE). We mainly discuss the experimental aspect of the optical properties of excitons in ZnO-based MQW heterostructures. Systematic temperature-dependent studies of optical absorption and photoluminescence in these MQWs were used to evaluate the well-width dependence and the composition dependence of the major excitonic properties. Based on these data, the localization of excitons, the influence of exciton-phonon interaction and quantum-confined Stark effects are discussed. The optical spectra of dense excitonic systems are shown to be determined mainly by the interaction process between excitons and biexcitons. The high-density excitonic effects play a role in the observation of room-temperature stimulated emission in the ZnO MQWs. The binding energies of exciton and biexciton are enhanced from the bulk values, as a result of quantum-confinement effects.