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.

Hydrogen plasma induced modification of photoluminescence from a-SiNx:H thin films

“…This exposure results in modifying both structural and optical properties. For example, defect passivation and rise or recovery in photoluminescence (PL) intensity has been reported in several materials like GaN, 16 a-Si:H and a-SiO 2 multilayers, 17 Si-QDs embedded in SiO 2 (Ref. 18) and SiC, 19 CdSe QDs in borosilicate glass.…”

Enhanced luminescence from Si quantum dots/SiO2 multilayers by hydrogen annealing

“…It has been reported that hydrogen atoms can passivate the defect states to improve the luminescence intensity and stability [17,18]. K. Sato et al reported that the PL intensity of nano-crystalline Si (nc-Si) can be increased more than one order of magnitude by using hydrofluoric acid solution to passivate the non-luminescence states [15].…”

Optoelectronic Properties of Amorphous Silicon the Role of Hydrogen: from Experiment to Modeling

“…The author identifies three stages, associated with low C H , medium C H , and high C H , that describe the changes in the stress and structure parameters. Rui et al (2005) investigated the effect of hydrogen plasma annealing on the micro-structural transition from disorder to order in amorphous silicon films. They found that there exist two steps for the reaction between atomic hydrogen and Si network, and show that the hydrogen plasma treatment conditions strongly influence the microstructures of the amorphous Si films The disorder inherent in the amorphous structure and the presence of dangling bonds has a crucial impact also on the electronic density of states (DOS) of amorphous silicon.…”