Temperature quenching of exciton luminescence intensity in ZnO/(Mg,Zn)O multiple quantum wells
Temperature quenching of exciton luminescence intensity in ZnO/(Mg,Zn)O multiple quantum wells
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DOI：
10.1063/1.1563295
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发表时间：
2003-05
影响因子：
3.2
通讯作者：
T. Makino;K. Tamura;C. Chia;Y. Segawa;M. Kawasaki;A. Ohtomo;H. Koinuma
中科院分区：
文献类型：
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作者：
T. Makino;K. Tamura;C. Chia;Y. Segawa;M. Kawasaki;A. Ohtomo;H. Koinuma
描述了在5-300K温度范围内观察到的激子光致发光的温度特性。在激光分子束外延生长的ZnO/Mg_(0.27)Zn_(0.73)O多量子阱中，在所研究的整个温度范围内，其发光以局域激子(LE)发射为主。没有观察到自由激子(FeS)的发光。用一个简单的速率方程描述了LE发射的猝灭过程。LE发光猝灭的激活能约为激子的局域化能量级，表明LES在局域势之外的热电子发射导致了非辐射复合。在具有较低势垒的ZnO/Mg_(0.12)Zn_(0.88)O多量子阱中，低温下发光主要以LE发射为主，而在175K以上则以Fe跃迁为主，用假设一个非辐射复合通道的速率方程描述发光猝灭。
The temperature-dependent behavior of excitonic photoluminescence observed in ZnO/MgZnO multiple quantum wells (MQWs) in the temperature range of 5–300 K is described. In a ZnO/Mg0.27Zn0.73O MQW grown by laser molecular-beam epitaxy, the luminescence was dominated by localized exciton (LE) emission throughout the whole temperature range studied. Luminescence of free excitons (FEs) was not observed. A simple rate equation is used to describe the quenching of LE emission. The activation energy for LE luminescence quenching is of the order of the localization energy of excitons, suggesting that the thermionic emission of the LEs out of the localization potentials leads to nonradiative recombination. In a ZnO/Mg0.12Zn0.88O MQW having lower barriers, the luminescence was dominated by LE emissions at low temperatures, while the FE transition was dominating emissions at temperatures above 175 K. A rate equation assuming one nonradiative recombination channel is used to describe the quenching of the transitions o...