Photostructural transformations in amorphous chalcogenide semiconductors
1994; Wiley; Volume: 183; Issue: 2 Linguagem: Inglês
10.1002/pssb.2221830203
ISSN1521-3951
Autores Tópico(s)Nonlinear Optical Materials Studies
ResumoAbstract The mechanism of photoinduced structural transformations in amorphous As 2 S 3 is studied with the differential IR Fourier spectroscopy technique in the 400 to 100 cm −1 region. It is established that the irreversible photostructural effect observed in freshly evaporated thin films is accompanied by switching of homopolar chemical bonds into heteropolar ones. The stage of reversible photodarkening is realized in a‐As 2 S 3 samples after a first cycle of photoexposure and thermoannealing. The corresponding destruction‐polymerization reaction is opposite to that obtained for irreversible changes. The whole scheme of photo‐ and thermoinduced structural transformations in a‐As 2 S 3 is presented as a multicyclic process of coordination defect formation and annihilation.
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