Surface morphology of spin-coated As-S-Se chalcogenide thin films

Surface morphology and roughness of amorphous spin-coated As-S-Se chalcogenide thin films were determined using atomic force microscopy. Prepared films were coated from butylamine solutions with thicknesses d similar to 100 nm and then annealed in a vacuum furnace at 45 degrees C and 90 degrees C for 1 h for their stabilization. The root mean square surface roughness analysis of surfaces of as-deposited spin-coated As-S-Se films indicated a very smooth film surface (with R-q values 0.42-0.45 +/- 0.2 nm depending on composition). The nanoscale images of as-deposited films confirmed that surface of the films is created by domains with dimensions 20-40 nm, which corresponds to diameters of clusters found in solutions. The domain character of film surfaces gradually disappeared with increasing annealing temperature while the solvent was removed from the films. Middle-infrared transmission spectra recorded a decrease of intensities of vibration bands connected to N-H (at 3367 and 3292 cm- 1) and C-H (at 2965, 2935 and 2880 cm(-1)) stretching vibrations. Temperature regions of solvent evaporation T-g = 60-90 degrees C and glass transformation temperatures T-g = 135-150 degrees C of spin-coated As-S-Se thin films were determined using a modulated differential scanning calorimetry. (C) 2007 Elsevier B.V. All rights reserved.