The optical constants of plasma-enhanced chemical-vapor-deposited amorphous silicon (<i>a</i>-Si:H) thin film upon a transparent substrate are determined within the UV–visible region by measurement of the transmittance spectrum. Apart from thickness irregularities, the effects of vertical film inhomogeneities (refractive-index distribution) on the spectrum are discussed. In this respect, although consideration of any possible variation in thickness of the film within the area illuminated by the probe beam is sufficient for correcting the modulation of the extrema of interference fringes, including in the model the thin transitional regions at substrate–film and film–air interfaces might be an alternative method for understanding the overall optical behavior of the spectrum.
© 2000 Optical Society of America
(160.2750) Materials : Glass and other amorphous materials
(300.6540) Spectroscopy : Spectroscopy, ultraviolet
(300.6550) Spectroscopy : Spectroscopy, visible
(310.6860) Thin films : Thin films, optical properties
Barış Akaoğlu, İsmail Atılgan, and Bayram Katırcıoğlu, "Correlation Between Optical Path Modulations and Transmittance Spectra of a-Si:H Thin Films," Appl. Opt. 39, 1611-1616 (2000)