In this study, zinc oxide nanoparticles have been synthesized in the presence of alkali hydroxides (NaOH and KOH) using the Sol-Gel method. The XRD, DLS, Z-scan, and UV–Vis spectroscopy were used to investigate nanoparticles' structural and optical properties. XRD diffraction patterns show enhancement in structural constants by adding sodium and especially potassium atoms. Correspondingly, the bandgap energy reduces because of decreasing the lattice energy. Also, the nonlinear absorption coefficient is measured using the z-scan technique, and it is found that reverse saturable absorption (RSA) is the prominent nonlinear optical phenomenon in this samples upon increasing the power of the incident laser beam and the magnitude of nonlinear absorption coefficient enhance by introducing Na and K atoms into the ZnO (named as NZO and KZO, respectively) crystal lattice. In accordance with the enhancement of nonlinear absorption processes, NZO and KZO are bestowed with optical bistability characteristics, which is beneficial for manufacturing optical switchers.

在这项研究中，使用溶胶-凝胶法在碱性氢氧化物（NaOH 和 KOH）存在下合成了氧化锌纳米颗粒。XRD、DLS、Z 扫描和紫外-可见光谱用于研究纳米颗粒的结构和光学特性。XRD 衍射图显示通过添加钠原子，尤其是钾原子，结构常数得到增强。相应地，由于晶格能量降低，带隙能量降低。此外，使用z-scan技术测量非线性吸收系数，发现随着入射激光束的功率和非线性吸收的幅度增加，反饱和吸收（RSA）是该样品中突出的非线性光学现象。通过将 Na 和 K 原子引入 ZnO（命名为 NZO 和 KZO，分别）晶格。根据非线性吸收过程的增强，NZO和KZO被赋予了光学双稳态特性，有利于制造光开关。