Molecular beam epitaxy of high structural quality Bi2Se3 on lattice matched InP(111) substrates

Abstract

Epitaxial layers of the topological insulator Bi 2 Se 3 have been grown by molecular beam epitaxy on laterally lattice-matched InP(111)B substrates. High resolution X-ray diffraction shows a significant improvement of Bi 2 Se 3 crystal quality compared to layers deposited on other substrates. The measured full width at half maximum of the rocking curve is ∆ω = 13 arcsec, and the (ω − 2θ) scans exhibit clear layer thickness fringes. Atomic force microscope images show triangular twin domains with sizes increasing with layer thickness. The structural quality of the domains is confirmed on the microscopic level by transmission electron microscopy.

Band bending driven evolution of the bound electron states at the interface between a three-dimensional topological insulator and a three-dimensional normal insulator

“…Angle-resolved photoelectron spectroscopy (ARPES) and conductivity measurements in the Bi 2 Te 3 thin films deposited on Si(111) [40,41], InP [42], GaAs [43], and Al 2 O 3 [44] [23] clearly demonstrated that the band bending appearing in the TI film leads to substantial separation of the probability maxima and energy spectra of the surface (TSS) and interfacial (TIS and/or OIS) quasiparticles. Unfortunately, detailed study of the interfacial electron states in this system, which requires separation of TIS and OIS contributions, has not been performed yet.…”

High-quality Bi2Te3 thin films grown on mica substrates for potential optoelectronic applications

“…10 Previously, the surfaces of Bi 2 Te 3 or Bi 2 Se 3 thin film often comprised some domains of pyramidal-shape terraces or so-called triangular spirals; consequently, depending on the thickness of the thin films, a large number of valleys/voids with varied depths/sizes could exist in between two adjacent domains. 5,11 In sharp contrast, the terraces of our Bi 2 Te 3 thin films on mica present nearly full coverage of the entire surface over a large area with only one or two QLs variation in thickness. The absence of spirals on the terraces, together with the shape of the terrace, suggests a favorable growth dynamics accounting for the high crystalline quality of TI on mica.…”

“…Additionally, due to the spirals growth behavior, the steps and voids are produced among the terraces on the surfaces of the thin films, giving rise to a small effective surface conductance. [3][4][5][6] One promising approach to improve the crystalline quality is to grow thin films on weakly interacting substrates via van der Waals epitaxy (vdWE), which facilitates the growth of a defect-free epilayer with its own lattice parameters even from the first layer. 7 Muscovite mica with a stoichiometry of KAl 3 Si 3 O 10 (OH) 2 is a well-known substrate that favors the vdWE growth of semiconductors, metal thin films, and welloriented nanowire arrays.…”

Topological Insulator Materials

“…In particular, epitaxial growths of Bi 2 Se 3 have been reported for various substrates including Si(111), [181][182][183][184] grapheneterminated 6H-SiC(0001), 174,185) SrTiO 3 (111), 186) GaAs (111), 187) sapphire (0001), 173,188,189) CdS(0001), 190) and InP (111). 191) It turned out that the control of the substrate temperature is the most crucial ingredient for obtaining high-quality films of Bi 2 Se 3 with a large area of atomically flat terraces. 189) In particular, a two-step method in which the depositions of the first layer and subsequent layers are done at different temperatures, to promote initial adhesion and crystallization separately, has been reported to yield best quality films.…”