Structure and photo-induced volume changes of obliquely deposited amorphous selenium

TL;DR

This study uses atomic scale simulations to explore how oblique deposition affects the structure and photo-induced volume changes in amorphous selenium films, revealing defect formation and structural dynamics.

Contribution

It provides new insights into the microscopic mechanisms of photo-induced changes in obliquely deposited chalcogenide glasses, highlighting the role of voids and defects.

Findings

Obliquely deposited films have more defects and larger voids.

Photo excitation causes covalent and interchain bond breakage.

Void-rich samples exhibit significant structural and volume changes.

Abstract

Atomic scale computer simulations on structures and photo induced volume changes of flatly and obliquely deposited amorphous selenium films have been carried out in order to understand how the properties of chalcogenide glasses are influenced by their preparation method. Obliquely deposited a-Se thin films contain more coordination defects, larger voids than the flatly deposited ones. To model the photo induced volume changes the electron excitation and hole creation were treated independently within the framework of tight-binding formalism. Covalent and interchain bond breakings and formations were found. The obliquely deposited samples containing voids showed a wide spectrum of photo induced structural changes in microscopic and volume changes in macroscopic levels.