Deposition and characterization of solution processed Se-rich Ge-Se thin films with specular optical quality using multi-component solvent approach

Abstract

The Ge25Se75, Ge20Se80 and Ge15Se85 thin films were deposited in specular optical quality from n-propylamine - methanol solvent mixture by spin-coating technique. As-prepared solution processed thin films were thermally stabilized to reduce the content of organic solvent residuals and optical properties, surface topography, composition, structure and chemical resistance of prepared Ge-Se thin films were studied in dependence of annealing temperature. Suitable thermal stabilization temperatures were found for each studied chalcogenide glass composition with respect to maintaining of thin films’ low surface roughness and targeted elemental composition. Stabilized thin films exhibited high refractive index, high chemical resistance, low surface roughness and structure close to source bulk glasses. The experiments proved that used n-propylamine - methanol solvent offered suitable way for preparation of high optical quality Ge-Se thin films by solution based deposition route.

Solution processed multi-layered thin films of Ge20Sb5S75 and Ge20Sb5Se75 chalcogenide glasses

“…A probable cause could be expected in partial Se evaporation due to its significant overstoichiometry in the glass. The observed phenomenon is in good agreement with similar results described on solution processed glasses from Ge-Se compositional system 30 .

Figure 1 Annealing temperature dependence of the glass composition.

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“…The presence of this shoulder can be attributed to Ge–Ge vibration in Ge 2 Se 6/2 structural unit 46 , 47 . An increase in the intensity of the background between the two main bands and the presence of a new band at 110 cm −1 suggests the presence of the amorphous Se 30 , 48 . Another new band at 323 cm −1 occurs in the Raman spectrum of as-prepared thin film.…”

“…2 ). The content of the nitrogen in the thin film is directly linked to the content of the organic residua of PrNH 2 incorporated in the structure of the glass 30 , 41 . Because all thin films were deposited and also annealed in oxygen free atmosphere, content of the oxygen in the thin films is mainly connected with residua of MeOH, which was used in the solvent mixture.…”

“…The majority of solution processed chalcogenide thin film research has been done on glasses from an As-S compositional system (mostly As 2 S 3 ), which will hardly reach any practical application due to the toxicity of the arsenic and low chemical resistance of prepared films. Lately, we can observe a shift of the scientific interest to non-toxic Ge-based glasses 30 , 31 , particularly to glasses from Ge–Sb–S system 32 – 34 .…”

Thermally Induced Silane Dehydrocoupling: Hydrophobic and Oleophilic Filter Paper Preparation for Water Separation and Removal from Organic Solvents

“…Organic solvents are widely used in various fields, including optical, electronic, pharmaceutical, and chemical industries, and their quality control is directly related to product quality [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 ]. Many factors may reduce the purity of organic solvents, and water is considered the most noticeable impurity [ 13 , 14 , 15 ].…”