Thermally-Induced Structural Evolution of Silicon- and Oxygen-Containing Hydrogenated Amorphous Carbon

TL;DR

This study investigates how silicon and oxygen incorporation affects the thermal stability and structural evolution of hydrogenated amorphous carbon using spectroscopy and molecular dynamics simulations.

Contribution

It provides new insights into the thermal stability mechanisms of silicon- and oxygen-containing amorphous carbon materials.

Findings

Si and O increase activation energy for sp3 to sp2 conversion

a-C:H:Si:O has higher thermal stability than a-C:H

Lower fraction of strained C-C sp3 bonds in a-C:H:Si:O

Abstract

The thermally-induced structural evolution of silicon- and oxygen-containing hydrogenated amorphous carbon (a-C:H:Si:O) was investigated by X-ray photoelectron and absorption spectroscopy, as well as molecular dynamics (MD) simulations. The spectroscopic results indicate that the introduction of Si and O in hydrogenated amorphous carbon (a-C:H) increases the activation energy for the conversion of sp3- to sp2-bonded C. MD simulations indicate that the higher thermal stability of a-C:H:Si:O compared to a-C:H derives from the lower fraction of strained C-C sp3 bonds in a-C:H:Si:O.