Effect of α-irradiation and Ge content for a-Si:H and a-Si:H/a-Ge:H with different layer films is studied on infrared (IR) spectra. The integrated intensity of the oscillator strength of Si-H and Ge-H vibrations is determined. It is found that the integrated intensities of IR vibrational bands are enhanced significantly after the bombardment by 0.5 MeV α-particles. These observations are explained in terms of the change in the oscillation strengths of the vibrational modes induced by defects created near the vibration complex during bombardment. The results reveal that the effect of Ge content on the infrared spectra before and after irradiated films by α-particles of energy 125KeV/n. The defects were created by bombardments induce an increase in the oscillator strengths for some of Si-H and Ge-H vibrations due to decrease in the refractive index . The dangling bonds were formed in the range 2700-3100cm-1 in a-Si:H/a-Ge:H in attributed to the presence of OH groups or due to the preferential attachment of hydrogen and deuterium to Si atoms rather than the Ge ones. The irradiated a-Si:H/a-Ge:H lead to decrease the absorption band due to increase the hydrogen content bonded to Ge atoms, therefore the disorder is decreased and the crystalline state is increased.