Optical dispersion relations for amorphous semiconductors and amorphous dielectrics

✍ Scribed by Forouhi, A. R.; Bloomer, I.

• Book ID: 118046062
• Publisher: The American Physical Society
• Year: 1986
• Tongue: English
• Weight: 849 KB
• Volume: 34
• Category: Article
• ISSN: 1098-0121
• DOI: 10.1103/physrevb.34.7018

✦ Synopsis

An expression for the imaginary part, k, of the complex index of refraction, N = n -ik, for amor- phous materials is derived as a function of photon energy E: k{E)=A(E -Eg) /(E -8E+C)

where A, 8, and C are positive nonzero constants characteristic of the medium such that 4 C 8 & 0 Eg represents the optical energy band gap. The real part, n, of the complex index of refraction is then determined to be n(E)=n( 00)+(80E+Co)/ (E2 -8E+C) using Kramers- Kronig analysis, where 8o and Co are constants that depend on A, 8, C"and Eg, and n(00) is a constant greater than unity. Excellent agreement was found between these formulas and experimen- tally measured and published values of n and k of amorphous silicon, hydrogenated amorphous sil- icon, amorphous silicon nitride, and titanium dioxide.