Effect of bath temperature on physical properties of thin films CuO using the SILAR method: Photocatalytic properties and numerical investigation

Abstract

Copper oxide (CuO) thin films were deposited on glass substrates using the Successive Ionic Layer Adsorption and Reaction (SILAR) method, these films synthesized cationic solution temperatures of room temperature (RT), 65 °C, 75 °C, and 95 °C. The effects of varying cationic solution temperatures on the structural, optical, and photocatalytic properties of the CuO thin films were investigated. Characterization was performed using X-ray diffraction (XRD), UV–visible spectrophotometry (UV–Vis), and scanning electron microscopy (SEM). The XRD and SEM results revealed that all films exhibited a polycrystalline structure with monoclinic phases and good substrate coverage. The optical bandgap energy decreased from 1.92 eV to 1.74 eV as the cationic solution temperature increased. Additionally, the photocatalytic performance was evaluated by measuring the degradation of a 10 ppm tetracycline solution. The efficiencies improved from 11.1 % at RT to 18.4 % at 95 °C. Finally, a numerical analysis was conducted using the SCAPS simulation software, employing the identified optimal bandgap of 1.74 eV for degradation. The simulation involved creating a PN junction device with a CuO HTL and different electron transport layers (ETLs: ZnO, TiO₂, WS2 and SnO₂), to examine the effect of CuO film thickness and the shallow doping concentrations of the acceptors (CuO) and donors (ETLs) on current density.