Quantum mechanical calculations of optical absorption of CdS and CdSe quantum dots
Quantum mechanical calculations of optical absorption of CdS and CdSe quantum dots
复制标题
DOI：
10.1179/143307511x13031890747859
复制
发表时间：
2011-08-01
影响因子：
--
通讯作者：
Saion, E.
中科院分区：
文献类型：
--
作者：
Gharibshahi, E.;Saion, E.
半导体 CdS 量子点 (QD) 因其与块状量子点不同寻常的物理特性以及在非线性光学、光电化学、光催化和单电子晶体管中的潜在应用而引起了广泛关注。在这项工作中，利用密度函数理论量子力学计算了 CdS 和 CdSe QD 的光学吸收光谱。这一新进展基于 Thomas-Fermi-Dirac-Weizsacker 原子系统的基态能量泛函的时间无关薛定谔方程，以及最终欧拉-拉格朗日方程中具有吸收函数的代数替换密度函数。对具有面心立方晶格原始晶胞结构的孤立 CdS 和 CdSe QD 的总能量泛函进行了数值计算。结果表明，随着颗粒尺寸的增加，CdS 和 CdSe QD 吸收峰增加到更高的波长。量子点的带隙随着直径的增加而减小，对应于构建颗粒尺寸所需的原始细胞的数量。
Semiconductor CdS quantum dots (QDs) have attracted considerable attention owing to their unusual physical properties from their bulk counterparts and potential applications in non-linear optics, photoelectrochemicals, photocatalysis and single electron transistors. In this work, the optical absorption spectra of CdS and CdSe QDs were calculated quantum mechanically using density function theory. This new development is based on the time independent Schrodinger equation of the ground state energy functional of the Thomas-Fermi-Dirac-Weizsacker atomic system and by algebraically substituted density function in the final Euler-Lagrange equation with the absorption function. The total energy functional was computed numerically for isolated CdS and CdSe QDs having face centred cubic lattice primitive cell structure. The results showed that the CdS and CdSe QD absorption peak increases to higher wavelengths with increasing particle size. The bandgap of the QDs decreases with increasing diameter corresponding to the number of primitive cells needed to construct the particle size.