Effect of α-Irradiation of energy 0.5 Mev on hydrogen bonding in a-Si : h and ultrathin layers of a-Si: H-a-Ge : H

Abstract EN

The Effect of α-irradiation and Ge content on a-Si: H and a-Si: H/a-Ge: H with different layer films are studied using 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 strength of the vibrational modes induced by defects created near the vibration complex during bombardment.

The results revealed the effect of Ge content on the infrared spectra before and after irradiated films by α-particles of energy 125KeV/n.

The defectsو 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, formed in the range of 2700-3100 cm-1 in a-Si: H/a-Ge: H, are 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 decreasing the absorption band due to the increase in the hydrogen content bonded to Ge atoms.

Therefore, the disorder is decreased and the crystalline state is increased.