Light-induced anelastic change in a-Si(H)

The thermal desorption spectra between 400 and 1100 K and the internal friction spectra between 80 and 423 K were studied for a-Si(H). The thermal desorption of hydrogen was observed around 650 K (TDH650 K) and around 900 K (TDH900 K,L and TDH900 K,H). Both TDH900 K,L and TDH900 K,H with the activation energy of 1.6 eV were attributed to the desorption of bonded hydrogen. TDH650 K was not a diffusion controlled process with the activation energy of 1.0 eV, where one part of TDH650 K was attributed to the desorption of isolated hydrogen molecules. The hydrogen-induced internal friction, H-Qa-Si(H)−1, was observed between 80 and 423 K. Hydrogen responsible for H-Qa-Si(H)−1 showed the thermal desorption around 650 K (TDH650 K), indicating that isolated hydrogen molecules in the amorphous structure may be responsible for H-Qa-Si(H)−1. Light soaking caused changes in H-Qa-Si(H)−1 in the temperature ranges between 80 and 200 K and between 200 and 300 K, indicating that light soaking modified the local amorphous structures responsible for these changes in Qa-Si(H)−1.