Calculation of the thickness and optical constants of amorphous arsenic sulphide films from their transmission spectra

Abstract

The interference modulated transmission spectra T( lambda ) at normal incidence for amorphous arsenic sulphide semiconducting films deposited by thermal evaporation were obtained in the spectral region from 300 nm up to 2000 nm. The straightforward analysis proposed by Swanepoel (1983), which is based on the use of the extremes of the interference fringes, has been applied in order to derive the real and imaginary parts of the complex index of refraction and also the film thickness. Thickness measurements made by a surface profiling stylus have also been carried out to cross check the results obtained by the method employing only T( lambda ). In addition, the optical band gap Egopt has been determined from the absorption coefficient values using Tauc's procedure, i.e. from the relationship alpha (h nu )=K(h nu -Egopt)2/h nu , where K is a constant. Finally, it is emphasised that accurate results were achieved not only with the above mentioned glass composition As2S3, but also in the case of the non-stoichiometric composition As30S70.

Influence of annealing conditions on the optical and structural properties of spin-coated As_2S_3 chalcogenide glass thin films

“…In the weak and medium absorption region, the refractive index dispersion can be calculated using Swanepoel's method [21,22]. The optical band gaps opt g E of the films as a function of the annealing temperature are determined through Tauc's extrapolation as presented in Fig.…”

“…Using Swanepoel's method on the transmission spectra [21,22], the refractive index dispersion for the films are calculated.…”

Synthesis, Optical and Electrical Properties of ZnFe2O4 Nanocomposites

“…ZnFe2O4 has been known to have strong absorption in the UV-Vis range [15,16,17]. As shown in Figure 6, the ZnFe2O4 nanocomposites have strong band edge absorption in the wavelength region of 250 to 800nm.…”

Influencia del contenido metálico sobre las constantes ópticas de laminas delgadas amorfas de composición As₃₃S₆₇ fotodopadas con Ag

“…asImIsmo, el espesor se deTermInó Como el promedIo de aquellos Valores lIsTados en la Columna d 1 . el sIgnIfICado de Todos los parámeTros que apareCen en la Tabla, esTá explICado Con Todo deTalle en oTros Trabajos de esTos mIsmos auTores (15,16). …”

“…La Ec. [3] permite determinar, además, el correspondiente espesor de la lámina, d. Todos los detalles sobre la aplicación práctica del algoritmo utilizado para el cálculo del índice de refracción y del espesor de las muestras en estudio, pueden encontrarse detalladamente explicados en anteriores publicaciones de los autores (15,16). Asimismo, en la tabla I se recogen los resultados de la aplicación de este algoritmo, para la muestra dopada de composición química Ag 16.5 As 27.6 S 55.…”