Effect of Te doping in GeSe parent thick film by experimental in situ temperature-dependent structural investigation

TL;DR

This study investigates how tellurium doping affects the structural transformation and local atomic environments in GeSe thin films during heating, revealing changes in crystallization temperature and local disorder.

Contribution

It provides experimental in situ structural insights into Te doping effects on GeSe films, highlighting modifications in crystallization behavior and atomic environments.

Findings

Te doping alters the crystallization temperature and phase symmetry.

Significant changes in local atomic environments occur during amorphous to crystalline transition.

Te substitution increases local structural disorder in GeSe films.

Abstract

As-deposited and unencapsulated GeSe$_{1-x}$Te$_x$ ($x = 0, 0.25$) 3-$\mu$m-thick amorphous films on Si(001) were obtained via the co-evaporation technique to study the effect of selenium (Se) substitution for tellurium (Te) on the GeSe parent structure in the function of the heating temperature. In situ, grazing-incidence X-ray scattering (XRS), and fluorescence X-ray Absorption Near Edge Structure (XANES) data were collected in isochronal annealing conditions under nitrogen flow. The results show that the onset temperature of crystallization $T_c$ and the crystallized phase symmetry are susceptible to the Te 25 at. % doping. Furthermore, Ge and Se K-edge XANES analyses reveal significant alterations in the local atomic environments surrounding Ge and Se atoms during the transition from the amorphous to the crystalline state. These modifications are accompanied by an observable increase in local structural disorder upon substitution with Te atoms.