Scanning tunneling microscopy study of epitaxial growth of PbSe thin film on

Abstract

Abstract Epitaxial growth of PbSe thin film on BaF 2 ( 1 1 1 ) is studied by means of scanning tunneling microscopy (STM). The results showed that the structures and morphologies of PbSe thin films depend crucially on Pb-to-Se atomic ratio in the growth of PbSe film. For the PbSe film grown with an atomic ratio of Pb / Se ≈ 1 at a substrate temperature of 450 ∘ C , the morphologies are dominated by two interlocked spirals around threading dislocation. Meanwhile, for the PbSe film grown with a higher Pb-to-Se atomic ratio, besides some spirals structures, the V-defects appear in the film. PbSe growth on BaF 2 ( 1 1 1 ) is in the step-flow mode, and the formation of the V-defects in the case of the PbSe film growth with a higher Pb-to-Se atomic ratio can be attributed to excessive Pb atoms congregating in the dislocation core area and relatively slow growth rate of ( 1 0 0 ) facets.