Journal of Theoretical and Applied Physics (JTAP) Influence of heat treatment on the efficiency ofWO3: Au NPs optoelectronic device prepared by spray pyrolysis technique Volume 18 (2024) Special Issue-AICIS’23 2024 07 25 Influence of heat treatment on the efficiency ofWO3: Au NPs optoelectronic device prepared by spray pyrolysis technique 10.57647/j.jtap.2024.si-AICIS23.07 EN Mohammed Hamid Mustafa Department of Physics, College of Education for Pure Science Ibn Al-Haitham, University of Baghdad, Baghdad, Iraq 0000-0002-9256-8562 Aliyah A. Shihab Department of Physics, College of Education for Pure Science Ibn Al-Haitham, University of Baghdad, Baghdad, Iraq 0000-0003-0793-1943 Journal Article 2024 07 25 By using pyrolysis spray technique, tungsten dioxide films doped with gold nanoparticles were successfully deposited on glass and silicon substrates at 320 ◦C. Au-WO3 films were annealed for one hour at 673 (K) and 873 (K). A number of physical characteristics of the prepared and annealed films have been examined using atomic force microscopy, UV-visible spectroscopy, X-ray diffraction and other techniques. It was discovered that the indirect energy gap in the UV-visible spectrum of as-prepared and annealed thin films decrease after annealing from 2.86 eV to 2.42 eV, and according to the structure properties, the prepared and annealed thin films had an amorphous structure at substrate temperature 320 ◦C, but they had a polycrystalline structure at annealing temperature. The samples’ cubic structures for gold nanoparticles and monoclinic structures for tungsten trioxide were also revealed. The thin layer of all sample can be seen to have a nanostructure thanks to atomic force microscopy. All prepared films, whether doped with gold, or those that have been annealed at 673,873 (K), are shown by Hall effect measurements to have a negative Hall coefficient. This indicates that prepared films are of n-type, and have highest conductivity and mobility of carriers, respectively 10.52×10−5 Ω.cm−1 and 476.45 cm2/V.S, and that the highest efficiency of the WO3: Au/Si (1.804%) was attained when measurements current-volt under illumination.