Abstract

In this paper, the optical absorption coefficient of a core/shell quantum dot near a bimetallic nanoparticle is maximized. For this purpose, the Schrödinger equation is solved by numerical methods to obtain the exciton energy. Then by using the density matrix method, the absorption coefficient of the hybrid system is calculated. Afterward, by applying the particle swarm optimization (PSO) algorithm, the absorption coefficient of the system is optimized. After obtaining the optimum structure, the refractive index changes, the electric field enhancement factor for the core/shell quantum dot, and the near-field enhancement for the bimetallic nanoparticle are examined. Additionally, the optical absorption coefficient is calculated for different radii of the bimetallic nanoparticle and for different distances between the surfaces of the core/shell quantum dot and the bimetallic nanoparticle. Then it is compared with that of the optimum structure. The results show that the absorption coefficient of the optimum structure is 3.41 × 10⁶ (m⁻¹) and its electric field enhancement increases up to 9 times.

Graphical abstract

中文翻译：

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优化双金属纳米粒子附近的核/壳量子点的光吸收系数

摘要

在本文中，双金属纳米粒子附近的核/壳量子点的光吸收系数最大。为此，通过数值方法求解薛定ding方程以获得激子能量。然后通过使用密度矩阵法，计算混合系统的吸收系数。之后，通过应用粒子群算法（PSO）对系统的吸收系数进行优化。在获得最佳结构后，检查折射率变化，核/壳量子点的电场增强因子以及双金属纳米粒子的近场增强。另外，对于双金属纳米颗粒的不同半径以及在核/壳量子点的表面与双金属纳米颗粒之间的不同距离，计算光吸收系数。然后将其与最佳结构进行比较。结果表明，最佳结构的吸收系数为3.41×10^在图6  （m ^-1）中，其电场增强增加到9倍。

图形概要