Aluminum-doped zinc oxide (ZnO) is a semiconductor material with a wide band gap energy of approximately 3.4 eV and a high binding energy of around 60 meV. These characteristics confer several advantages, including the ability to withstand high breakdown voltages and sustain large electric fields. The inclusion of aluminum also enhances the electrical conductivity of zinc oxide. In this study, we employed a hydrothermal method, using zinc acetate as the source of ZnO, to synthesize AZO nanoparticles by incorporating aluminum. We conducted a thorough examination of the structural, morphological, and electrical properties of these Al-doped ZnO nanoparticles using X-ray diffraction (XRD), scanning electron microscopy (SEM), and Hall effect measurements. Additionally, we utilized the synthesized AZO as a buffer layer in CZTS-based solar cells, with the structure [Mo/ CZTS /CdS/AZO/Au], achieving a commendable conversion efficiency of 5%.