Characterization of textured SnO2:F layers by ellipsometry using glass-side illumination

Abstract

Spectroscopic ellipsometry (SE), in which the probe light is illuminated from a glass substrate side, has been applied for the characterization of textured SnO2:F layers formed on glass substrates. This approach can basically be employed for the non-destructive characterization of the component layers in silicon thin-film solar cells formed on large-area glass substrates, even when the backside metal electrodes are present. To perform the accurate characterization of the SnO2:F textured structure, the SE spectra obtained from the glass-side and conventional film-side illuminations are analyzed simultaneously by using the identical dielectric functions and optical models. In this study, the layer thickness and optical carrier concentration of the textured SnO2:F layer have been deduced from the SE analysis using the Drude model, and the estimated values from SE show excellent agreement with those obtained by other techniques. From the SE results, we demonstrate that the SE analysis using the glass-side illumination can be performed even for the textured structures.