The composition and film thickness of organic layered photoconductors containing the charge generation dyes hydroxysquarilium and chlorodiane blue are analyzed by specular reflectance infrared spectroscopy. The analysis involves recording the infrared spectrum of the photoconductor after the dye layer is coated onto an appropriate substrate. Since the IR spectra are recorded in a specular reflection mode, modeling is required in order to understand the relationship between reflectance and film thickness for the dye layers. Thus a dispersion analysis is used to determine the complex refractive indices over the infrared for the charge generation dyes hydroxysquarilium and chlorodiane blue.
J. Pacansky, R. J. Waltman, and R. Grygier, "An Analysis for the Composition and Film Thickness of Organic Layered Photoconductors. Part I: Complex Refractive Indices over the Infrared for Hydroxysquarilium and Chlorodiane Blue Charge Generation Dyes," Appl. Spectrosc. 43, 1233-1240 (1989)