Exciton transport and nonradiative decay in semiconductor nanostructures
Exciton transport and nonradiative decay in semiconductor nanostructures
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半导体纳米结构中的激子输运和非辐射衰变
DOI：
10.1103/physrevb.58.10687
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发表时间：
1998
期刊：
影响因子：
--
通讯作者：
D. J. Wolford
中科院分区：
文献类型：
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作者：
I. Krivorotov;T. Chang;G. D. Gilliland;L. P. Fu;K. Bajaj;D. J. Wolford
描述激子光致发光的现象学理论 ~PL！本文提出了 II 型超晶格的动力学，其中考虑了由于“无序”界面周围的界面缺陷捕获激子而导致的本征激子辐射衰变和非辐射衰变。因此，我们研究了系统维数对这些非辐射衰变动力学细节的影响。对于有效的三维和二维结构，该理论预测随着温度的升高，从强非指数衰减动力学到近指数衰减动力学的转变。相比之下，对于一维结构，预计衰变动力学在所有温度下都是非指数的。利用这些预测，我们应用该模型来解释我们在特定短周期 II 型 GaAs/AlAs 超晶格上观察到的时间分辨 PL。因此，这些 PL 衰变可以在 ~2-30 K 的较宽温度范围内得到解释！以及观察到的从非指数行为到指数行为的交叉。该模型使我们能够从实验数据中提取非辐射缺陷密度和平均辐射衰变率。 @S0163-1829~98!03940-X#
A phenomenological theory describing the exciton photoluminescence ~PL! kinetics in type-II superlattices is proposed herein, which takes into account both the intrinsic exciton radiative decay and nonradiative decay due to exciton trapping by interfacial defects surrounding a ‘‘disordered’’ interface. We have thus investigated the effect of system dimensionality on details of these nonradiative-decay kinetics. For effectively threedimensional and two-dimensional structures, the theory predicts a transition from strongly nonexponential to nearly exponential decay kinetics as the temperature is increased. Contrastingly, for one-dimensional structures the decay kinetics is predicted to be nonexponential at all temperatures. Using these predictions, we have applied this model to explain our observed time-resolved PL on specific short-period type-II GaAs/AlAs superlattices. These PL decays are thus explained both over a wide range of temperatures ~2‐30 K! and over an observed crossover from nonexponential to exponential behavior. The model allows us to extract a nonradiative-defect density and an average radiative-decay rate from the experimental data. @S0163-1829~98!03940-X#