1. Structural, optical and electrical properties of RF-sputtered a-SiGe:H:O alloys
- Author
-
Shashanka S. Mitra, J.M.T. Pereira, and P.K. Banerjee
- Subjects
Hydrogen ,Silicon ,Chemistry ,business.industry ,Analytical chemistry ,chemistry.chemical_element ,Substrate (electronics) ,Conductivity ,Condensed Matter Physics ,Oxygen ,Electronic, Optical and Magnetic Materials ,Amorphous solid ,Optics ,Tauc plot ,Materials Chemistry ,Ceramics and Composites ,business ,Refractive index - Abstract
Amorphous thin films of Si x Ge 1- x :H:O ( x = 0.70) were prepared by RF-sputtering at several substrate temperatures. The structural properties of these films were studied by IR spectroscopy and revealed features characteristic of hydrogen and/or oxygen bonded to silicon. The optical constants ( n, k ) were determined from reflection and transmission measurements at near-normal incidence for photon energies in the range of 1 and 2.6 eV. The optical gap was derived from the Tauc plot and correlated with the composition of the samples. The increase of hydrogen and/or oxygen decreases the value of refractive index and increases the optical gap. The room temperature DC conductivity can be reduced by as much as four orders of magnitude by combining the effects of hydrogen and oxygen compensation and for the concentrations used. The dependence of the conductivity on the atomic concentrations of hydrogen and/or oxygen follows a similar trend as the refractive index.
- Published
- 1987