ملخص: We establish a relation to determine optical absorption coefficients ([alpha]) of weakly absorbing films from the ratio between absorptance A and transmittance T measurements. This relation is tested successfully on hydrogenated amorphous germanium (a:Ge:H) films studied by a combination of standard optical transmission measurements and photothermal deflection spectroscopy experiments. The [alpha]-spectra exhibit interference fringes which can be eliminated by the ratio A/T provided the thickness of the films are optically homogeneous.

لغة: إنجليزية