Morphological and Structural Characteristics of Sb2Se3 Thin Films Fabricated by Chemical Molecular Beam Deposition

Abstract

This work presents the structural and morphological characteristics of antimony selenide (Sb₂Se₃) thin films, which were deposited by the chemical molecular beam deposition (CMBD) in atmospheric pressure hydrogen flow on an alkali glass substrate. It was found that the deposition temperature affected the morphology and structure of the films. At a low deposition temperature of 720 K, the film depicts a preferable crystal orientation (211), i.e., one-dimensional (1D) Sb₂Se₃ ribbons are aligned along the growth direction. Morphological studies show that the grain size increases with the temperature of the substrate; however, the 1D Sb₂Se₃ chains tend to align along the lateral direction. The Sb₂Se₃ films were found to have a preferable orientation (211) and polycrystalline structure. At higher substrate temperatures of 770 and 820 K, they also have a polycrystalline structure, but with an orientation (120). The studies of surface morphology show that at low substrate temperatures the samples have fine grains that have sizes of (200–300) nm, but are rather tightly packed and have 1D Sb₂Se₃ chains, which are aligned along the growth direction that corresponds to the orientation (211). It was found that the Sb₂Se₃ thin films with the orientation (211) were suitable for an absorber layer of solar cells, due to their anisotropic properties.