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Stereoisomerism

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Updated: Jul 13, 2025

Electrospray Deposition of Uniform Thickness Ge23Sb7S70 and As40S60 Chalcogenide Glass Films

Electrospray Deposition of Uniform Thickness Ge23Sb7S70 and As40S60 Chalcogenide Glass Films

Published on: August 19, 2016

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

This summary is machine-generated.

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.

Keywords:

chalcogenide glasses density functional theory photostructural changes polymorphism

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In-situ Tapering of Chalcogenide Fiber for Mid-infrared Supercontinuum Generation

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Published on: May 27, 2013

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.