Random lasing emission was investigated from different ZnO nanostructures: a transition from nanowalls to nanoflakes; prepared on seeded glass substrate using simple chemical bath deposition method. The transition geometry of ZnO nanostructures were achieved simply by tuning the equimolar concentration of the chemical bath solution, zinc nitrate hexahydrate, and hexamethylenetetramine from 0.15 M, 0.20 M to 0.25 M. This leads to the changes in particle size of nanostructures from 168.47 nm to 365.91 nm, and finally to 534.07 nm. The population decreased from 131 nanostructures to 100, and finally to 26 nanostructures based on a surface area of 2.8 µm × 2.5 µm, and accordingly enhanced crystallite size was observed as 90.21 nm, 98.04 nm to 110.79 nm for the nanowalls to nanoflakes respectively. These physical variations of the scattering medium affect random lasing emission threshold whereby the threshold excitation power density was reduced from 40 kW/cm² to 17.14 kW/cm², and finally to 14.29 kW/cm² when the structure was in the form of nanoflakes. The emission wavelength from the structures shows a Stokes shift pattern and self-reliant while maintaining a stable emission at 379.7 nm (0.15 M), 382.7 nm (0.20 M), and 387.2 nm (0.25 M). This work demonstrates that by simply tuning the chemical bath solution molarities, changes in nanostructures from nanowalls to nanoflakes were obtained, and upon optical pumping, nanoflakes showed the lowest threshold for random lasing to occur indicating the best structure for ZnO random lasers.

研究了不同 ZnO 纳米结构的随机激光发射：从纳米壁到纳米薄片的转变；使用简单的化学浴沉积方法在晶种玻璃基板上制备。ZnO 纳米结构的过渡几何结构简单地通过将化学浴溶液、六水合硝酸锌和六亚甲基四胺的等摩尔浓度从 0.15 M、0.20 M 调整到 0.25 M 来实现。这导致纳米结构的粒径从 168.47 nm 变为365.91 nm，最后到 534.07 nm。基于 2.8 µm × 2.5 µm 的表面积，数量从 131 个纳米结构减少到 100 个，最后减少到 26 个纳米结构，因此观察到纳米壁到纳米薄片的微晶尺寸分别增加为 90.21 nm、98.04 nm 到 110.79 nm。²至 17.14 kW/cm ²，最终达到 14.29 kW/cm ²当结构为纳米薄片形式时。来自结构的发射波长显示出斯托克斯位移模式和自依赖，同时在 379.7 nm (0.15 M)、382.7 nm (0.20 M) 和 387.2 nm (0.25 M) 处保持稳定发射。这项工作表明，通过简单地调整化学浴溶液摩尔浓度，可以获得从纳米壁到纳米薄片的纳米结构变化，并且在光泵浦时，纳米薄片显示出随机激光发生的最低阈值，表明 ZnO 随机激光器的最佳结构。