Structural basis of temperature-dependent electrical resistance of evaporation-deposited amorphous GeSe film

Abstract

We employ EXAFS spectroscopy to refine the local atomic arrangements of evaporation-deposited equiatomic GeSe film. Amorphous structure of the as-deposited GeSe film turns out to satisfy mainly the 4:2 structural model. The crystallized GeSe film, however, consists of the orthorhombic GeSe crystals with the 3:3 atomic arrangements and quasi-crystalline Ge clusters. Its temperature-dependent electrical resistance is explained in connection with this structural difference, which exemplifies significance of the chemical environments on the electrical switching phenomena observed from amorphous chalcogenide solids.