Chalcogenide amorphous

Finally, more details about TOF experiments in various chalcogenide amorphous semiconductors may be found in the articles of the authors listed at the end of this chapter [44-53]. 

Intense research into optical characteristics of photoresists based on chalcogenide amorphous glasses has brought about the need for a device that would allow for such materials to be studied and adapted for the use in manufacturing technologies. 

Perspectives for fabrication of improved oxygen electrodes at a low cost have been offered by non-noble, transition metal catalysts, although their intrinsic catalytic activity and stability are lower in comparison with those of Pt and Pt-alloys. The vast majority of these materials comprise (1) macrocyclic metal transition complexes of the N4-type having Fe or Co as the central metal ion, i.e., porphyrins, phthalocyanines, and tetraazaannulenes [6-8] (2) transition metal carbides, nitrides, and oxides (e.g., FeCjc, TaOjcNy, MnOx) and (3) transition metal chalcogenide cluster compounds based on Chevrel phases, and Ru-based cluster/amorphous systems that contain chalcogen elements, mostly selenium. 

Binary systems of ruthenium sulfide or selenide nanoparticles (RujcSy, RujcSey) are considered as the state-of-the-art ORR electrocatalysts in the class of non-Chevrel amorphous transition metal chalcogenides. Notably, in contrast to pyrite-type MS2 varieties (typically RUS2) utilized in industrial catalysis as effective cathodes for the molecular oxygen reduction in acid medium, these Ru-based cluster materials exhibit a fairly robust activity even in high methanol content environments of fuel cells. 

Chern, G. C. Lauks, 1.1982. Spin-coated amorphous chalcogenide films. J. Applied Phys. 53 6979-6982. 

Thus far, only metal-oxide nanotubes have been synthesized by this process. Whereas crystalline nanotubes were obtained from 2D (layered) oxides, various 3D oxide compounds resulted in semicrystalline or amorphous nanotubes, only. In principle, this kind of process could be extended to the synthesis of nanotubes from chalcogenide and halide compounds in the future. 

Preparation of amorphous products The preparation of metals (Fe, Co, Ni, Pd, Au), alloys (Au-Pd, Fe-Co, etc.), oxides, chalcogenides, etc. has been reported. The synthesis of sulphides, for instance, has been obtained in solutions (in water, ethanol, etc.) of the metal chloride or acetate using thioacetamide or thiourea as sulphur precursor. 

The gap states in amorphous materials are known to result in charged defects, transport occurring through the hopping of bipolarons. In chalcogenide glasses, the bipolarons correspond to over-coordinated (Cj) and under-coordinated (Cj") centres. 

General aspects of the TSDC theory are discussed in an excellent review [2], The main emphasis in this text is on experimental use of the TSDC method for amorphous chalcogenide semiconductors and on corresponding results for these intriguing objects. 

Thermally Stimulated Depolarization Currents in Amorphous Chalcogenides... 

This section contains a review of results on the extensive study of defect states in the mobility gap of amorphous As- and Sb-containing chalcogenide semiconductors by relaxation technique. For extracting typical features, elemental selenium and simple compositions with relatively low content of arsenic and antimony are exemplified as possible. We will try to attribute TSDC peaks to charge carriers released from the respective trapping levels in the band gap of these materials. 

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