Reversible photodarkening and structural changes in As<sub>2</sub>S<sub>3</sub> thin films

Frumar, M.; Firth, Adam; Owen, A.E.

doi:10.1080/13642818408238871

Cited by 102 publications

(25 citation statements)

References 15 publications

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“…The Raman spectrum of the as-evaporated As 2 S 3 thin film measured in this work was found to be similar to that reported in a previous study [28]. This spectrum exhibits strong bands at 345 and 365 cm -1 , and several sharp features in the region 100 to 250 cm -1 (Fig.…”

Section: D) Raman Spectra Of Light Irradiated As 2 S 3 Thin Filmssupporting

confidence: 74%

Spectroscopic studies of bulk AS 2 S 3 glasses and amorphous films doped with Dy, Sm and Mn

et al. 2002

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The effect of rare earth (Dy and Sm) and transition metal (Mn) luminescent impurities on the optical properties of As 2 S 3 glass is studied in a wide spectral region. The Raman, infrared, band-to-band and edge absorption spectroscopies are employed to obtain information about the incorporation of impurity ions in the host glass structure and the corresponding changes in intrinsic optical characteristics. The effects of light-soaking and thermal treatment on the doped As 2 S 3 glasses were examined as well. In the fundamental absorption region a reflectivity maximum at 2.98 eV shows blue (Dy, Sm) or red (Mn) shift depending on the electronegativity of the impurity, in accordance with the corresponding variations of the glass structure. Near the edge absorption the impurity affects strongly the slope and the magnitude of the weak absorption tail. In the wide range of transparency the addition of impurity suppresses several absorption bands indicating the interaction of dopants with the host glass contaminations. Some variations of the characteristic Raman spectra under light exposure and thermal ageing of doped glasses were registered. The observed effects of metal dopants on the As 2 S 3 glass are discussed in connection with the expected behaviour of the impurities in the glass.

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Section: D) Raman Spectra Of Light Irradiated As 2 S 3 Thin Filmssupporting

confidence: 74%

Spectroscopic studies of bulk AS 2 S 3 glasses and amorphous films doped with Dy, Sm and Mn

et al. 2002

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“…Ranam scattering and EXAFS (extended X-ray absorption fine structure) studies have shown that the number of socalled "wrong bonds" (such as As-As bonds in stoichiometric As 2 S 3 glass which ideally should contain only As-S bonds) increased reversibly under irradiation [13,14]. This result, together with the finding that the photodarkening increased strongly in As-rich glasses [15], suggested a special role of arsenic in the process.…”

Section: Introductionsupporting

confidence: 54%

“…It consists in bond switching via the formation of dynamic bonds due to photo-excitation of LP-electrons of chalcogen atoms. The process in binary chalcogenides is more complicated since, in addition to coordination defects, also stoichiometric defects ("wrong bonds") can be induced in the material through the formation of dynamic interchalcogen bonds [13,14,21].…”

Section: Photo-induced Processes In Binary Chalcogenidesmentioning

confidence: 99%

Nanoscale mechanism of photoinduced metastability and reversible photodarkening in chalcogenide vitreous semiconductors

Kolobov

Tanaka²

1998

Semiconductors

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The present paper reviews the results oblained by the authors in the last three years. By applying in-situ (pamp and probe) EXAFS to reversible photostructural changes in chalcogenide vitreous semiconductors we have found an increase in the average coordination number of selenium species in the photoexcited state which comes from the formation of dynamic interchain bonds. Subsequent bond rupture, studied by optically-induced ESR, results in the formation of over-and undercoordinated ESR-active defects which are further transformed into charged valencealternation pairs. Annealing close to the glass-transition temperature results in recovery of the initial structure. Relationship between the detected structural changes and photodarkening is also discussed.

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“…Regarding structural changes induced by illumination, it is demonstrated through vibrational studies that heteropolar bonds are converted to homopolar bonds, i.e., As-S to As-As and S-S. 1,30,31 The conversion may cause the volume expansion, since the bond length of As-As ͓2.57 Å ͑Ref. 32͔͒ is longer than that of As-S ͓2.24 Å ͑Ref.…”

Section: A Origin Of the Photoexpansionmentioning

confidence: 99%

Photoexpansion inAs2S3glass

Tanaka

1998

Phys. Rev. B

149

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Mechanisms of photoexpansion in chalcogenide glasses have been studied in three respects. A detailed x-ray investigation of As 2 S 3 shows that the photoexpansion can be connected with asymmetric broadening of the first sharp diffraction peak. Comparison between radiation-induced volume changes and density ratios of glassyto-crystalline forms in As 2 S 3 and SiO 2 implies that As 2 S 3 can expand since the glass is as dense as its crystal. When As 2 S 3 is exposed to illumination, the photoexpansion appears earlier and later than the photodarkening for bandgap and subbandgap illumination, respectively. These observations are discussed from a microscopic point of view. ͓S0163-1829͑98͒09209-1͔

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Reversible photodarkening and structural changes in As₂S₃ thin films

Cited by 102 publications

References 15 publications

Spectroscopic studies of bulk AS 2 S 3 glasses and amorphous films doped with Dy, Sm and Mn

Spectroscopic studies of bulk AS 2 S 3 glasses and amorphous films doped with Dy, Sm and Mn

Nanoscale mechanism of photoinduced metastability and reversible photodarkening in chalcogenide vitreous semiconductors

Photoexpansion inAs2S3glass

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Reversible photodarkening and structural changes in As2S3 thin films

Cited by 102 publications

References 15 publications

Spectroscopic studies of bulk AS 2 S 3 glasses and amorphous films doped with Dy, Sm and Mn

Spectroscopic studies of bulk AS 2 S 3 glasses and amorphous films doped with Dy, Sm and Mn

Nanoscale mechanism of photoinduced metastability and reversible photodarkening in chalcogenide vitreous semiconductors

Photoexpansion inAs2S3glass

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Reversible photodarkening and structural changes in As₂S₃ thin films