Determination of Optical Constants: a-Si

✍ Scribed by G. Jungk

• Publisher: John Wiley and Sons
• Year: 1973
• Tongue: English
• Weight: 335 KB
• Volume: 55
• Category: Article
• ISSN: 0370-1972
• DOI: 10.1002/pssb.2220550213

✦ Synopsis

Abstract

Optical studies of a‐Si samples are reported. The dielectric function was determined ellipsometrically from 2.0 to 4.0 eV. Different concentrations of slit‐like voids may account for the variation of the optical constants in the investigated films. The depolarization factor L of the voids was estimated to 0.75 5 ≦ L ≦ 0.9. A structure of the optical constants near 3.5 eV indicates an exciton‐like transition. The extrapolation of the hv √ E~2~eff curves points to a pseudogap of the ideal a‐Si comparable with the indirect gap of the crystalline phase. These pseudogaps increase with increasing void‐concentration.