MBE growth optimization of topological insulator Bi2Te3 films

✍ Scribed by J. Krumrain; G. Mussler; S. Borisova; T. Stoica; L. Plucinski; C.M. Schneider; D. Grützmacher

• Book ID: 104022395
• Publisher: Elsevier Science
• Year: 2011
• Tongue: English
• Weight: 716 KB
• Volume: 324
• Category: Article
• ISSN: 0022-0248
• DOI: 10.1016/j.jcrysgro.2011.03.008

✦ Synopsis

We investigated the growth of the topological insulator Bi 2 Te 3 on Si(1 1 1) substrates by means of molecular-beam epitaxy (MBE). The substrate temperature as well as the Bi and Te beam-equivalent pressure (BEP) was varied in a large range. The structure and morphology of the layers were studied using X-ray diffraction (XRD), X-ray reflectivity (XRR) and atomic force microscopy (AFM). The layerby-layer growth mode with quintuple layer (QL) as an unit is accomplished on large plateaus if the MBE growth takes place in a Te overpressure. At carefully optimized MBE growth parameters, we obtained atomically smooth, single-crystal Bi 2 Te 3 with large area single QL covering about 75% of the layer surface. Angular-resolved photoelectron spectroscopy reveals a linear energy dispersion of charge carriers at the surface, evidencing topologically insulating properties of the Bi 2 Te 3 epilayers.