Uncertainties of transmittance and absorbance measurements of the chalcogenide thin films

Abstract

The uncertainties of the optical transmission and absorbance measurements of thin films GexSb40−xSe60 (x = 12, 25, and 30 at.%) are investigated in this paper. To obtain additional measurements, a technique is proposed based on the global volumetric deformation technique. The thin films are synthesized from elements with 5 N purity (Ge, Sb, Se) by the conventional melt-quenching method. The spectrophotometer’s measurements are recorded on Lambda 950 UV/VIS/NIR with double beam and double monochromator at room temperature, in the spectral range UV–VIS–NIR, with 266 nm/min a scanning speed. The optical transmission and absorbance spectra of the films are measured in the wavelength range of 640–1700 nm. The results of this investigation show that the uncertainties obtained from the measurement certificate chalcogenide layers such as Standard Reference Materials for routine applications in spectrophotometry. The uncertainties values are certificated to 0.002 and 0.003 percent of the value. They are principally due to inherent inhomogeneity and instability of the glass, surface effects, and position of filters.