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

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.