Thin films of the (Ga_xIn_1-x)₂O₃ compound have been prepared on Si substrates by the aerosol deposition method with variation of the Ga concentration (x) from 0 to 0.95. Indium chloride (InCl₃) and gallium nitrate (Ga(NO₃)₃) were used as precursors. The morphology, chemical composition, and crystal structure of the obtained films have been investigated by scanning electron microscopy (SEM), energy dispersive X-ray (EDX) and X-ray diffraction (XRD) analysis. The vibration modes have been deduced from Raman spectroscopy measurements to gain additional data concerning the crystallographic structure of phases constituting the deposited films. The optical absorption spectra were analyzed at room temperature in order to determine the bandgap as a function of the x-value in thin films. The photoresponse of films was investigated under the radiation with wavelength from the ultraviolet (UV), visible, and infrared (IR) spectral intervals. The performed investigations demonstrated the polycrystalline nature of films, consisting of high quality nanocrystals, ensuring a gradual increasing of the bandgap from 3.50 eV to 4.85 eV with increasing the x-value from 0 to 0.95, and a predominant photoresponse in the UV spectral range.