Abstract
In this work, rapid thermal annealing (RTA) was applied to multi-zinc oxide with doped bismuth layers (ZnO:Bi) on indium tin oxide substrate in the ambient atmosphere resulting in significant improvement of the conductive of multi- ZnO:Bi layers/ITO films. ITO is commonly used as conductive transparent electrodes for an electron transport layer (ETL) of perovskite solar cells. Spherical nano-crystalline ZnO:Bi film was obtained at 520 °C that inevitably affects unstable ITO conductivity. RTA process was subjected at varying conditions (700-930 °C for 20 s). It is found that the RTA process can obtain ZnO:Bi nanostructure, good optical property, and ITO conductivity improvement, simultaneously. The surface morphology of nc-ZnO:Bi films with a 10-20nm diameter size provide low reflectance and high transmittance at 3% and 90%, respectively, in the light wavelength between 250-850 nm. Highly conductive spherical nc-ZnO:Bi multilayers and stable conductivity ITO were obtained after RTA treatment. Thus, the high quality of such spherical nc-ZnO:Bi/ITO films could be used to produce ETL layer for further emerging solar cells and transparent contact electrodes for low-cost semiconductor devices.