Hydrogen diffusion and mobile hydrogen in amorphous silicon
1999; American Physical Society; Volume: 60; Issue: 11 Linguagem: Inglês
10.1103/physrevb.60.7725
ISSN1095-3795
Autores Tópico(s)Silicon Nanostructures and Photoluminescence
ResumoDiffusion phenomena in hydrogenated amorphous silicon $(a\ensuremath{-}\mathrm{S}\mathrm{i}:\mathrm{H})$ are modeled assuming that mobile H excited from Si-H bonds normally annihilates at dangling-bond defects, as in the ``H collision'' model of light-induced metastability. This diffusion model explains the long-standing puzzle of the doping dependence of the hydrogen diffusion coefficient ${D}_{\mathrm{H}}.$ It also yields the magnitudes of the ${D}_{\mathrm{H}}$ Arrhenius prefactors in doped and undoped $a\ensuremath{-}\mathrm{S}\mathrm{i}:\mathrm{H}.$ Mobile H diffuses over an energy barrier of about 0.3 eV; at room temperature, its diffusion rate is slightly greater than that of H in crystalline Si.
Referência(s)