Characterization of some optical and physical properties of As11.2S48.0Sb28.8Te12.0 and As20.8S48.0Sb19.2Te12.0 nanostructured polycrystalline semiconductors

Abstract

This work presents the characterization of As-S-Sb-Te nanostructured polycrystalline semiconductors by X-ray fluorescence (XRF), X-ray diffraction (XRD), electron microscopy (SEM), optical as well as photoelectric methods. The XRD patterns have been shown the presence of amorphous and nanocrystalline phases with the main structural units As2S3, Sb2S3 and Sb2Те3. The IR transmission spectra show a high transparence just with a single weak absorption band about ν=2340 cm-1 caused of the presence of H2S impurity. It was also observed that for the alloys of As11.2S48.0Sb28.8Te12.0 and As20.8S48.0Sb19.2Te12.0, with an increase in the number of As atoms, the transmission in the IR region also increase. The maximum of steady-state photoconductivity for both materials, measured in the linear portion of I-V characteristics, is situated around =0.96 m.

Synthesis and optical properties of the glassy compound As0.63S2.70Sb1.37Te0.30

“…This paper presents the extension of our previous experimental studies [5,6] regarding new chalcogenide materials in quaternal As-S-Sb-Te system. As shown in our early paper [5] chalcogenide materials, which have the composition similar to this one, namely As 11.2 S 48.0 Sb 28.8 Te 12.0 and As 20.8 S 48.0 Sb 19.2 Te 12.0 demonstrate polycrystalline structure.…”

Steady-state and transient photocurrents of As-S-Sb-Te amorphous thin films

“…Some experimental results on XRD, EDS and micro-Raman spectroscopy of As-S-Sb-Te system as bulk, powder and thin film samples were reported in [7,8]. It has been shown that the quaternary compounds As 1.17 S 2.7 Sb 0.83 Te 0.40 , As 1.04 S 2.4 Sb 0.96 Te 0.60 and As 0.56 S 2.4 Sb 1.44 Te 0.60 have a polycrystalline structure, and the other one As 0.63 S 2.7 Sb 1.37 Te 0.30 has a amorphous structure with broad peaks specific for non-crystalline materials.…”

“…It has been shown that the quaternary compounds As 1.17 S 2.7 Sb 0.83 Te 0.40 , As 1.04 S 2.4 Sb 0.96 Te 0.60 and As 0.56 S 2.4 Sb 1.44 Te 0.60 have a polycrystalline structure, and the other one As 0.63 S 2.7 Sb 1.37 Te 0.30 has a amorphous structure with broad peaks specific for non-crystalline materials. Studying of photoelectric properties allows obtaining information about the generation and recombination processes in chalcogenide semiconductors [7][8][9][10].…”

“…It was shown that with increasing of Te concentration in the alloys, the maximum of photoconductivity is shifted towards red region of the spectra from 800 nm to 950 nm. In [7] the results on the spectral distribution of steady-state photocurrent in bulk As As, S, Sb, and Te are high photosensitive amorphous materials, and widely are used as photodetectors and recording media of optical information. On the other hand, semiconductors containing elements Sb and Te are well known as "ovonic" materials for volatile memory.…”

Structural analysis of As-S-Sb-Te polycrystalline nanostructured semiconductors

“…The parameters for Sb 2 S 3 -As 2 S 3 -Sb 2 Te 3 compositions were calculated from their chemical formula obtained by EDS experiments [8]. Some optical and physical properties of As 11.2 S 48.0 Sb 28.8 Te 12.0 and As 20.8 S 48.0 Sb 19.2 Te 12.0 nano-structured polycrystalline semiconductors were reported in [9,10].…”