Selective light-induced mass transport in amorphous $As_{x}Se_{100-x}$ films driven by the composition tuning: effect of temperature on maximum acceleration

TL;DR

This study investigates how temperature influences light-induced mass transport in amorphous As-Se films, revealing a composition-dependent change in transport direction and significantly increased rates near the glass transition temperature.

Contribution

It introduces a model explaining the composition-dependent mass transport reversal and demonstrates temperature's effect on transport rates using Kelvin probe force microscopy.

Findings

Mass transport direction reverses in specific composition range.

Transport rates increase significantly near Tg.

Model qualitatively explains the observed phenomena.

Abstract

Under irradiation of amorphous $As_{x}Se_{100-x}$ films by band-gap light, it was observed that lateral mass transport of the film material changed the direction of movement in the region (4 < x < 5 at%.) of topological structural transition (crossover "from light to dark" to "from dark to light"). We propose a model that qualitatively describes the observed phenomenon. In experimental testing of the model by Kelvin probe force microscopy, for the first time to our knowledge, it was detected that with the increase of temperature (from ambient to glass-transition temperature, Tg) photo-induced mass transport in glassy semiconductors occurs with the rates, which significantly exceed those at room temperature.