{"title":"Low-defect-density SnSe2 films nucleated via thin layer crystallization","authors":"S.A. Ponomarev , K.E. Zakhozhev , D.I. Rogilo , A.K. Gutakovsky , N.N. Kurus , K.A. Kokh , D.V. Sheglov , A.G. Milekhin , A.V. Latyshev","doi":"10.1016/j.jcrysgro.2024.127615","DOIUrl":null,"url":null,"abstract":"<div><p>We have studied the structural and morphological features of SnSe<sub>2</sub> films grown on Si(111) and Bi<sub>2</sub>Se<sub>3</sub>(0001) surfaces in an <em>in situ</em> reflection electron microscope. On both substrates, the SnSe<sub>2</sub> growth started at 100 °C as an amorphous layer, and when thickness reached 1 nm, crystallized by raising the growth temperature to 250 °C without interruption of Sn and Se fluxes. The introduction of this growth-initiating stage has decreased the concentration of screw dislocations on films’ surfaces to ∼18 and ∼2 μm<sup>−2</sup> for the Si(111) and Bi<sub>2</sub>Se<sub>3</sub>(0001) substrates, respectively. High-resolution transmission electron microscopy investigation has shown that the layered SnSe<sub>2</sub> film has a hexagonal lattice structure corresponding to the space group <span><math><mrow><mtext>P</mtext><mover><mrow><mn>3</mn></mrow><mrow><mo>¯</mo></mrow></mover><mtext>m</mtext><mn>1</mn></mrow></math></span> (no. 164) with lattice parameters <em>a</em> = 0.38 nm and <em>c</em> = 0.62 nm. Raman spectroscopy has shown vibrational modes corresponding to the 1T-SnSe<sub>2</sub> phase. We have shown that the decrease in Se:Sn flux ratio switches growth mode from Frank—van der Merwe type SnSe<sub>2</sub> epitaxy to Volmer—Weber type nucleation of SnSe 3D islands.</p></div>","PeriodicalId":353,"journal":{"name":"Journal of Crystal Growth","volume":null,"pages":null},"PeriodicalIF":1.7000,"publicationDate":"2024-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Crystal Growth","FirstCategoryId":"88","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0022024824000502","RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"CRYSTALLOGRAPHY","Score":null,"Total":0}
引用次数: 0
Abstract
We have studied the structural and morphological features of SnSe2 films grown on Si(111) and Bi2Se3(0001) surfaces in an in situ reflection electron microscope. On both substrates, the SnSe2 growth started at 100 °C as an amorphous layer, and when thickness reached 1 nm, crystallized by raising the growth temperature to 250 °C without interruption of Sn and Se fluxes. The introduction of this growth-initiating stage has decreased the concentration of screw dislocations on films’ surfaces to ∼18 and ∼2 μm−2 for the Si(111) and Bi2Se3(0001) substrates, respectively. High-resolution transmission electron microscopy investigation has shown that the layered SnSe2 film has a hexagonal lattice structure corresponding to the space group (no. 164) with lattice parameters a = 0.38 nm and c = 0.62 nm. Raman spectroscopy has shown vibrational modes corresponding to the 1T-SnSe2 phase. We have shown that the decrease in Se:Sn flux ratio switches growth mode from Frank—van der Merwe type SnSe2 epitaxy to Volmer—Weber type nucleation of SnSe 3D islands.
期刊介绍:
The journal offers a common reference and publication source for workers engaged in research on the experimental and theoretical aspects of crystal growth and its applications, e.g. in devices. Experimental and theoretical contributions are published in the following fields: theory of nucleation and growth, molecular kinetics and transport phenomena, crystallization in viscous media such as polymers and glasses; crystal growth of metals, minerals, semiconductors, superconductors, magnetics, inorganic, organic and biological substances in bulk or as thin films; molecular beam epitaxy, chemical vapor deposition, growth of III-V and II-VI and other semiconductors; characterization of single crystals by physical and chemical methods; apparatus, instrumentation and techniques for crystal growth, and purification methods; multilayer heterostructures and their characterisation with an emphasis on crystal growth and epitaxial aspects of electronic materials. A special feature of the journal is the periodic inclusion of proceedings of symposia and conferences on relevant aspects of crystal growth.