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Updated: Jul 13, 2025
08:38
Electrospray Deposition of Uniform Thickness Ge23Sb7S70 and As40S60 Chalcogenide Glass Films
Published on: August 19, 2016
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Lone-Pair-Enabled Polymorphism and Photostructural Changes in Chalcogenide Glasses
Alexander V Kolobov1, Vladimir G Kuznetsov2, Milos Krbal3
1Institute of Physics, Herzen State Pedagogical University of Russia, 48 Moïka Emb., St. Petersburg 191186, Russia.
Materials (Basel, Switzerland)
|October 14, 2023
Summary
Chalcogenide glasses exhibit unique photo-induced effects. This study reveals that polymorphic transformations, specifically to tetradymite structure, significantly reduce the optical band gap in arsenic trisulfide (As2S3) glasses.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Photonics
Background:
- Sulfur- and Selenium-based chalcogenide glasses are metastable materials.
- They exhibit unique photo-induced effects like reversible photostructural changes and photo-induced anisotropy.
- These phenomena are often explained by valence alternation pairs and 'wrong' bonds.
Purpose of the Study:
- To investigate the impact of polymorphic transformations on the optical band gap of chalcogenide glasses.
- To explore the structural mechanisms behind photo-induced changes in these materials.
- To provide a novel perspective on the application of chalcogenide glasses in photonic devices.
Main Methods:
- Density functional theory (DFT) simulations were employed.
- The study focused on arsenic trisulfide (As2S3) as a case example.
- Analysis involved examining local structural transformations and their electronic properties.
Main Results:
- A significant decrease in the optical band gap of As2S3 was observed.
- This decrease is linked to a polymorphic transformation from the orpiment to the tetradymite local structure.
- The formation of the tetradymite structure requires lone-pair electrons in near-linear atomic configurations.
Conclusions:
- Polymorphism is a key factor in understanding photo-induced structural changes in chalcogenide glasses.
- The identified structural transformation offers a new mechanism for tuning optical properties.
- These findings could enhance the use of chalcogenide glasses in various photonic applications.
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