Structural defects and electronic phase diagram of topological insulator bismuth telluride epitaxial films

Fornari, Celso I.; Rappl, P. H. O.; Morelhão, Sérgio L.; Fornari, Gabriel; Travelho, J. S.; Castro, S. de; Pirralho, M. J. P.; Pena, F. S.; Peres, M. L.; Abramof, E.

doi:10.1088/2053-1591/aadeb7

Cited by 15 publications

(22 citation statements)

References 47 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The Bi 2 Te 3 consists of an atomic layers sequence Te (1) -Bi-Te (2) -Bi-Te (1) (Bi 2 Te 3 ). These layers are modified as Te (1) -Bi-Se (2) -Bi-Te (1) [24]. As a result, these layers are introduced with more and more stacking faults.…”

Section: Resultsmentioning

confidence: 99%

Improved electrical conductivity and power factor in Sn and Se co-doped melt-grown Bi2Te3 single crystal

Hegde

Prabhu

Chattopadhyay

2021

J Mater Sci: Mater Electron

View full text Add to dashboard Cite

In the current work, growth and thermoelectric characterization of tin and selenium co-doped single crystal bismuth telluride have been carried out in the range of temperature 10–400 K. The crystals show hexagonal crystal structure with R$$\overline{3 }$$ 3 ¯ m space group. The direction of growth, quality of the single crystals, the density of dislocation, and dopants effect on the inner plane structure of the crystals have been analyzed through high-resolution X-ray diffraction study. Energy dispersive analysis of X-rays approves the elemental composition, and field emission scanning electron microscopy shows uniform growth with micro precipitates on the surface of the crystals. Quasi degenerate and non-degenerate electrical resistivity is observed in the pristine and doped samples, respectively. Temperature-dependent Seebeck coefficient measurements confirm the n-type semiconducting nature of the pristine as well as doped samples. Temperature-dependent power factor of (Bi0.96Sn0.04)2Te2.7Se0.3 is found to increase by 1.1 times, and electrical resistivity reduced by 3.3 times as compared to pristine Bi2Te3.

show abstract

Section: Resultsmentioning

confidence: 99%

Improved electrical conductivity and power factor in Sn and Se co-doped melt-grown Bi2Te3 single crystal

Hegde

Prabhu

Chattopadhyay

2021

J Mater Sci: Mater Electron

View full text Add to dashboard Cite

show abstract

“…These spectra are well understood in terms of the Raman spectra of Te and Sb 2 Te 3 films. Te revealed the strongest vibrational peak at ∼120 cm −1 (A 1 mode) besides two peaks at ∼92 cm −1 and ∼140 cm −1 representing E modes (Fornari et al , 2018). On the other hand, crystalline Sb 2 Te 3 film had the characteristic Raman-active modes at ∼65 cm −1 (A 1g 1 ), ∼106 cm −1 (E g 2 ) and ∼ 138 cm −1 (A 1g 2 ) (Liu et al , 2015).…”

Section: Resultsmentioning

confidence: 99%

Eutectic Sb_7.4Te_92.6 thin film for non-volatile phase-change memories

Barbon

Bilovol

Liscia

et al. 2019

View full text Add to dashboard Cite

Purpose The purpose of this paper is to investigate the structure and electrical properties of eutectic Sb7.4Te92.6 as made thin films to evaluate their potentiality for application to non-volatile phase-change memories. Design/methodology/approach The films were prepared by the pulsed laser deposition technique. The films were characterized by using X-ray diffraction in grazing-incident geometry, differential scanning calorimetry, Raman spectroscopy and transversal current–voltage curves. Findings The memory effect state, characteristic of a typical phase-change memory material, was observed. The temperature of crystallization was about 100ºC. Research limitations/implications Further studies on endurance, scaling and SET/RESET operations are needed. Practical implications One of the main characteristic values, the hold voltage and the threshold voltage values, were about 0.85 and 1.2 V, respectively, in a line with those of Ge2Sb2Te5, GeTe and Sb2Te being considered to date as the main compounds for phase-change memory devices. Originality/value The conduction mechanism in the amorphous regime is highly agreed with the Poole–Frenkel effect in deep traps.

show abstract

“…The beam equivalent pressure (BEP) of the effusion cells was monitored by a Bayer-Alpert ion gauge. The extra tellurium supply Φ = ∑ BEP Te ∑ BEP Bi 2 Te 3 ⁄ is determined as the ratio between the Te and Bi2Te3 BEP [8]. In this case, Φ = 0 indicates that no extra tellurium is provided during the growth, that is films are grown by using only the Bi2Te3 cell.…”

Section: Methodsmentioning

confidence: 99%

Morphology Control in van der Waals Epitaxy of Bismuth Telluride Topological Insulators

et al. 2020

View full text Add to dashboard Cite

Bismuth telluride have regained significant attention as a prototype of topological insulator. Thin films of high quality have been investigated as a basic platform for novel spintronic devices. Low mobility of bismuth and high desorption coefficient of telluride compose a scenario where growth parameters have drastic effects on structural and electronic properties of the films. Recently [J. Phys. Chem. C 2019, 123, 24818−24825], a detailed investigation has been performed on the dynamics of defects in epitaxial films of this material, revealing the impact of film/substrate lattice misfit on the films’ lateral coherence. Very small lattice misfit (<0.05%) are expected to have no influence on quality of epitaxial system with atomic layers weakly bonded to each other by van der Waals forces, contrarily to what was observed. In this work, we investigate the correlation between lattice misfit and size and morphology of the film crystalline domains. Three-dimensional reciprocal-space maps of film Bragg reflections obtained with synchrotron X-rays are used to visualize the spatial conformation of the crystallographic domains through film thickness, while atomic force microscopy images provide direct information of the domains morphology at the film surface.

show abstract

Structural defects and electronic phase diagram of topological insulator bismuth telluride epitaxial films

Cited by 15 publications

References 47 publications

Improved electrical conductivity and power factor in Sn and Se co-doped melt-grown Bi2Te3 single crystal

Improved electrical conductivity and power factor in Sn and Se co-doped melt-grown Bi2Te3 single crystal

Eutectic Sb_7.4Te_92.6 thin film for non-volatile phase-change memories

Morphology Control in van der Waals Epitaxy of Bismuth Telluride Topological Insulators

Contact Info

Product

Resources

About

Structural defects and electronic phase diagram of topological insulator bismuth telluride epitaxial films

Cited by 15 publications

References 47 publications

Improved electrical conductivity and power factor in Sn and Se co-doped melt-grown Bi2Te3 single crystal

Improved electrical conductivity and power factor in Sn and Se co-doped melt-grown Bi2Te3 single crystal

Eutectic Sb7.4Te92.6 thin film for non-volatile phase-change memories

Morphology Control in van der Waals Epitaxy of Bismuth Telluride Topological Insulators

Contact Info

Product

Resources

About

Eutectic Sb_7.4Te_92.6 thin film for non-volatile phase-change memories