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Abstract: Pulsed laser deposition was used to prepare amorphous thin films from (GeSe2)100−x(Sb2Se3)x system (x = 0, 5, 10, 20, 30, 40, 50, and 60). From a wide variety of chalcogenide glass‐forming systems, Ge–Sb–Se one, especially in thin films form, already proved to offer a great potential for photonic devices such as chemical sensors. This system has a large glass‐forming region which gives the possibility to adjust the chemical composition of the glasses according to required physical characteristics. The chemical composition of fabricated thin films was analyzed via X‐ray photoelectron spectroscopy (XPS) and compared to energy dispersive spectroscopy (EDS) data. The results of both techniques agree well: a small deficiency in chalcogen element and an excess of antimony was found. The structure of as‐deposited thin films has been investigated by XPS. The presence of the two main structural units, [GeSe4] and [SbSe3] proposed by Raman scattering spectroscopy data analysis, was confirmed by XPS. Moreover, XPS core level spectra analysis revealed the presence of M–M bonds (M = Ge, Sb) in (Ge,Sb)–Ge–(Se)3 and (Ge,Sb)–Sb–(Se)2 entities that could correspond to Ge‐based tetrahedra and Sb‐based pyramids where one of its Se atoms at corners is substituted by Ge or Sb ones. The content of depicted M–M bonds tends to increase with introduction of antimony in the amorphous network of as‐deposited thin films from x = 0 to x = 40 and then it decreases. XPS analysis of as‐deposited thin films shows also the presence of the (Ge,Sb)–Se–(Ge,Sb) and Se–Se–(Ge,Sb) entities. [ABSTRACT FROM AUTHOR]

RATIONALE: GexAsyTe z glasses have a broad window of optical transparency and high refractive index which make them promising for applications in the infrared region. The aim of this work is to reveal structural motifs which could be present during the fabrication of Ge-As-Te thin films by plasma deposition techniques; such knowledge is important for the optimization of thin film growth. METHODS: Mass spectra were acquired using a laser desorption ionization time-of-flight (LDI-TOF) mass spectrometer equipped with a nitrogen laser (337 nm) coupled with a quadrupole ion trap, and recorded in positive and negative ion reflectron modes. XRD, SEM (EDX) and Raman spectroscopy were also used for the characterization of Ge-As-Te bulk or powdered samples. RESULTS: Bulk GexAsyTez samples (x = 10-20%, y = 20-60%, z = 30-70%) were synthesized. LDI-MS of Ge-As-Te powders provided evidence for the formation of both positively and negatively charged clusters, whose stoichiometry was determined as Ten+/- (n = 1-4), Te5+, binary AsTen+/- (n = 1-3), GeTen+/- (n = 1-3), As2Te +/-, As2Te 3+, As3Te +, AsTe4+, Ge2H6+/-, ternary GeAsTe+, GeAsTe2+/-, GeAsH5+, GeAsH6+, GeAsH12+, and tertiary GeAsTeH5-, GeAsTeH8-, GeAsTe2H3+/-. CONCLUSIONS: The local structure of GexAsyTez materials is at least partly different from that of species identified in plasma by mass spectrometry, as deduced from Raman scattering spectroscopy analysis. However, LDI-TOFMS was found to be a suitable technique for the partial structure characterization of Ge-As-Te bulk samples and especially for the identification of the structural motifs present in the plasma during the preparation of the corresponding thin films. [ABSTRACT FROM AUTHOR]

Variable angle spectroscopic ellipsometry technique was used to characterize optical functions of chalcogenide glasses from Ge-As-Te system in broad spectral range (300 nm-20 µm). Measured real and imaginary parts of pseudodielectric function were modeled with Cody-Lorentz approach and Sellmeier equation. Very good agreement between experimentally measured and modeled imaginary and real parts of pseudodielectric functions leads to precise determination of optical functions (refractive index, extinction coefficient) of studied Ge-As-Te glasses in extremely broad spectral range covering UV-Vis-NIR-MIR. The method is generally applicable for other glasses and amorphous materials. [ABSTRACT FROM AUTHOR]