Department of Physics, Faculty of Science, Firat University, 23119, Elazig, Turkey.
Kastamonu Univ, Res & Applicat Ctr, TR-37150, Kastamonu, Turkey.
J Mol Model. 2023 Jul 5;29(8):227. doi: 10.1007/s00894-023-05641-1.
In this study, theoretical and experimental analysis of the electrical, optical, and structural properties of a wurtzite-like zinc oxide (ZnO) nanostructure has been done. To investigate how quantum confinement affects the optical characteristics, two distinct ZnO clusters in nanowire structures have been investigated. The [(ZnO)(HO)] system's HOMO-LUMO band gap (BG) was calculated to be 2.99 eV, which is quite close to the experimental measurement. It was found that the BG decreases with the increase in the number of atoms in the cluster in connection with the quantum confinement in nanoclusters. In addition, the lowest excitation energy in TD-DFT calculations of the identical system is in fairly good agreement with the experimental value with a difference of 0.1 eV. We conclude that the CAM-B3LYP functional has highly successful in reproducing the experimental data reported in the present study and previously reported experimental data.
The geometrical optimization of two different sizes of ZnO clusters ([(ZnO)25(H2O)4] and [ZnO)55(H2O)4]) was performed using the CAM-B3LYP functional with no symmetry constraints applied in the gas phase. LANL2DZ basis sets were used for the Zinc (Zn) atom and 6-31G* basis sets for the O and H atoms. To determine their optical and electronic properties, excited state calculations of the pre-optimized structures were performed using the Time-Dependent DFT (TD-DFT) method. Multiwfn, Gaussum 3.0, and GaussView 5.0 programs were used to visualize the results.
本研究对纤锌矿型氧化锌（ZnO）纳米结构的电学、光学和结构性质进行了理论和实验分析。为了研究量子限域如何影响光学特性，研究了两种不同的 ZnO 纳米线结构中的纳米团簇。（ZnO）（HO）体系的 HOMO-LUMO 带隙（BG）计算值为 2.99 eV，与实验测量值非常接近。结果表明，BG 随着团簇中原子数量的增加而减小，这与纳米团簇中的量子限域有关。此外，相同体系的 TD-DFT 计算中最低激发能与实验值非常吻合，差值为 0.1 eV。我们得出结论，CAM-B3LYP 泛函在重现本研究和以前报道的实验数据方面非常成功。
使用无对称限制的气相 CAM-B3LYP 泛函对两种不同尺寸的 ZnO 团簇（[(ZnO)25(H2O)4]和[ZnO)55(H2O)4]）进行了几何优化。LANL2DZ 基组用于锌（Zn）原子，6-31G*基组用于 O 和 H 原子。为了确定它们的光学和电子性质，对预优化结构进行了激发态计算，使用了时间相关密度泛函（TD-DFT）方法。使用 Multiwfn、Gaussum 3.0 和 GaussView 5.0 程序可视化结果。
