Excitonic states in spherical layered quantum dots
Excitonic states in spherical layered quantum dots
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DOI：
10.1016/j.physe.2019.113755
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发表时间：
2020-02-01
影响因子：
3.3
通讯作者：
Osenda, Omar
中科院分区：
文献类型：
--
作者：
Garagiola, Mariano;Osenda, Omar
利用k研究了球形量子点中激子的性质。P方法在Hartree近似下的应用。所考虑的球形量子点有一个中心核心和几个由不同半导体材料组成的同心层，这些同心层被建模为一系列势垒和势垒。这个K。用自洽迭代方法求解了电子-空穴对的p哈密顿量和库仑方程。用非常精确的数值近似方法计算了空量子点和电子-空穴对的能谱。结果表明，激子结合能随量子点中心半径的变化呈现出强烈的非线性行为。特别是，对于具有两个势垒的量子点，结合能呈现出很大的陡峭变化。最后一种行为可以用不同材料界面的极化电荷和本征函数的匹配条件来解释。
The properties of excitons formed in spherical quantum dots are studied using the k . p method within the Hartree approximation. The spherical quantum dots considered have a central core and several concentric layers of different semiconductor materials that are modeled as a succession of potential wells and barriers. The k . p Hamiltonian and the Coulomb equations for the electron-hole pair are solved using a self-consistent iterative method. The calculation of the spectrum of the empty quantum dot and the electron-hole pair is performed by means of a very accurate numerical approximation. It is found that the exciton binding energy as a function of the core radius of the quantum dot shows a strong non-linear behavior. In particular, for quantum dots with two potential wells, the binding energy presents a large steep change. This last behavior is explained in terms of the polarization charges at the interfaces between different materials and the matching conditions for the eigenfunctions.