Electronic processes on the surface of AsSe chalcogenide glassy semiconductors

Mamontova, T. N.; Kochemirovskii, A. S.; Pivovarova, L. V.

doi:10.1002/pssa.2211070102

Cited by 8 publications

(2 citation statements)

References 30 publications

(10 reference statements)

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“…It is worth noting that such remarkable improvement in gas sensing parameters is achieved without heating, since the working temperature is kept at 22 °C (room temperature). The reason for such behavior seems to be due to the increase in the chemical activity of chalcogenides at the surface when disorder (amorphization) increases [ 32 – 33 ] and to the increase in the active area caused by substrate porosity. Another interesting feature observed in the experiments was the spontaneous reduction (or sometimes increase) in the gas-induced current upon step-change concentration of the target gas.…”

Section: Discussionmentioning

confidence: 99%

Gas-sensing features of nanostructured tellurium thin films

Tsiulyanu¹

2020

Beilstein J. Nanotechnol.

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Nanocrystalline and amorphous nanostructured tellurium (Te) thin films were grown and their gas-sensing properties were investigated at different operating temperatures with respect to scanning electron microscopy and X-ray diffraction analyses. It was shown that both types of films interacted with nitrogen dioxide, which resulted in a decrease of electrical conductivity. The gas sensitivity, as well as the response and recovery times, differed between these two nanostructured films. It is worth mentioning that these properties also depend on the operating temperature and the applied gas concentration on the films. An increase in the operating temperature decreased not only the response and recovery times but also the gas sensitivity of the nanocrystalline films. This shortcoming could be solved by using the amorphous nanostructured Te films which, even at 22 °C, exhibited higher gas sensitivity and shorter response and recovery times by more than one order of magnitude in comparison to the nanocrystalline Te films. These results were interpreted in terms of an increase in disorder (amorphization), leading to an increase in the surface chemical activity of chalcogenides, as well as an increase in the active surface area due to substrate porosity.

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Section: Discussionmentioning

confidence: 99%

Gas-sensing features of nanostructured tellurium thin films

Tsiulyanu¹

2020

Beilstein J. Nanotechnol.

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“…Further, the effect of mechanical and chemical surface treatment on spectral distribution and kinetics of photoconductivity of glassy As 2 Se 3 was discovered and investigated. Later, the effect of ambient gases on the surface photovoltage of Ge 16 As 35 Te 28 S 21 , as well as on the surface conductivity and photoconductivity of arsenic selenide was observed and studied. The real interest in effect of gas adsorption on electrical conductivity of ChGS appeared in the early 2000s, when the Ge–As–Te based gas sensors for atmospheric pollution control have been proposed .…”

Section: Introductionmentioning

confidence: 99%

On the Influence of Surface Phenomena Upon Charge Transport in Te‐Based Glassy Semiconductors

Tsiulyanu

Ciobanu

2018

Physica Status Solidi (b)

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The effect of surface phenomena caused by adsorption of NO 2 , CO 2 , and H 2 O vapor on the charge transport in thin films of chalcogenide glassy semiconductors (ChGS) of the As 2 S 3 Ge 8 -Te system has been studied. The investigations have been carried out by measuring the dynamic conductivity of these films in a large (5 to 10 7 Hz) frequency range, in both dry air and its mixture with controlled concentrations of the above mentioned gases at different temperatures. In addition to this, the temperature dependence of DC conductivity has also been measured for an unambiguous interpretation of the results. It is shown that depending on material's composition, the AC conductivity in dry air can either be frequency independent across the full range or be frequency independent until %10 4 Hz, with increasing σ(ω) % ω n (n % 0.7) at higher frequencies. This behavior demonstrates that for these glassy films there is a competition of several transport mechanisms, so that depending on frequency at normal temperatures the charge is carried: by free holes or by tunneling between localized states at either valence band edge or those near the Fermi level. An estimation has been made for the density of states at the Fermi level of As 2 S 3 Ge 8 Te 13 that appears to be N(E F ) % 1.3 Â 10 21 eV À1 cm À3 . Changes of environmental conditions either in air humidification or application of even very small (ppm) concentration of NO 2 dramatically influence the spectra of dynamic conductivity that, on the other hand, remain nearly unaffected upon CO 2 vapor application. This is evidence that for some chalcogenide materials the surface phenomena disturb the energetic distribution of states adjacent to surface, changing the transport mechanisms.

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Structure

Tanaka¹,

Shimakawa²

2011

Amorphous Chalcogenide Semiconductors and Related Materials

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Electronic processes on the surface of AsSe chalcogenide glassy semiconductors

Cited by 8 publications

References 30 publications

Gas-sensing features of nanostructured tellurium thin films

Gas-sensing features of nanostructured tellurium thin films

On the Influence of Surface Phenomena Upon Charge Transport in Te‐Based Glassy Semiconductors

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