A low-cost spin coating technique and rapid thermal annealing (RTA) methods have been utilized for the preparation of aluminum-doped zinc oxide (AZO) with a Si dots thin film on the quartz substrates. The dispersed Si dots particle in the film showed that these additional Si dots can be tunable material for light absorption applied in photovoltaic work. X-ray diffraction was used to study the nanocrystalline silicon and zinc oxide with the crystal grain size of ~ 100 and ~ 20 nm presented in the films, respectively. The optical result of the thin films shows that < 20% reflectance and > 80% transmittance were presented in the film. The absorption edge of thin films that have occupied Si dots was expanded from the original zinc oxide which strongly absorbs UV wavelengths (~380 nm) to near-infrared wavelength (~800 nm) depending on the amount of Si dots layer. For the electrical properties of the film, the two-probe method was used to observe the photocurrent gain under the illumination compared with the dark test and showed that the film can greatly respond to the light and provide higher current density values. Additionally, the increase in annealing temperature as RTA and the amount of zinc oxide layer leads to the enchantment of the current density. Hence, these zinc oxide thin films can be an alternative candidate for the tunable absorption emitter layer of solar cells and can be applied to optoelectronic devices.