Hydrogen-induced recovery of photoluminescence from annealed a-Si:H∕a-SiO2 multilayers

Abstract

a - Si : H ∕ Si O 2 multilayers prepared by plasma-enhanced chemical-vapor deposition exhibit a luminescence band around 760nm, which is quenched after a dehydrogenation process. Subsequent hydrogen plasma annealing (HPA) treatments are carried out, and the luminescence is then recovered. The effects of HPA are investigated as functions of hydrogen annealing time and temperature. Fourier transform infrared spectroscopy and Raman-scattering spectroscopy are used to study the change of the microstructures and bonding configurations due to the HPA treatments. It is indicated that the atomic hydrogen cannot only diffuse into the film to reduce the density of nonradiative recombination centers but can also relax the film network and improve the microstructure order of the a-Si:H sublayers. All these factors are believed to contribute to the recovery of the luminescence signals of the a-Si:H∕SiO2 multilayers.