Abstract
An expression for the imaginary part, k, of the complex index of refraction, N=n-ik, for amorphous materials is derived as a function of photon energy E: k(E)=A(E-/(-BE+C) where A, B, and C are positive nonzero constants characteristic of the medium such that 4C->0. represents the optical energy band gap. The real part, n, of the complex index of refraction is then determined to be n(E)=n(∞)+(E+)/ (-BE+C) using Kramers-Kronig analysis, where and are constants that depend on A, B, C, and , and n(∞) is a constant greater than unity. Excellent agreement was found between these formulas and experimentally measured and published values of n and k of amorphous silicon, hydrogenated amorphous silicon, amorphous silicon nitride, and titanium dioxide.
- Received 20 March 1986
DOI:https://doi.org/10.1103/PhysRevB.34.7018
©1986 American Physical Society