Interband absorption edge in the topological insulators
Bi-2(Te1-xSex)(3)

J 2017

Interband absorption edge in the topological insulators Bi-2(Te1-xSex)(3)

DUBROKA, Adam, Ondřej CAHA, Miloš HRONČEK, Pavel FRIŠ, Milan ORLITA et. al.

Basic information

Original name

Interband absorption edge in the topological insulators Bi-2(Te1-xSex)(3)

Authors

DUBROKA, Adam (203 Czech Republic, guarantor, belonging to the institution), Ondřej CAHA (203 Czech Republic, belonging to the institution), Miloš HRONČEK (703 Slovakia, belonging to the institution), Pavel FRIŠ (203 Czech Republic, belonging to the institution), Milan ORLITA (203 Czech Republic), Václav HOLÝ (203 Czech Republic, belonging to the institution), H. STEINER (40 Austria), Günther BAUER (40 Austria), Günter SPRINGHOLZ (40 Austria) and Josef HUMLÍČEK (203 Czech Republic, belonging to the institution)

Edition

Physical Review B, College PK, MD USA, AMER PHYSICAL SOC, 2017, 2469-9950

Other information

Language

English

Type of outcome

Článek v odborném periodiku

Field of Study

10302 Condensed matter physics

Country of publisher

United States of America

Confidentiality degree

není předmětem státního či obchodního tajemství

Impact factor

Impact factor: 3.813

RIV identification code

RIV/00216224:14310/17:00099464

Organization unit

Faculty of Science

DOI

http://dx.doi.org/10.1103/PhysRevB.96.235202

UT WoS

000417757200005

Keywords in English

BISMUTH TELLURIDE; BI2SE3; SURFACE; BI2TE3; CRYSTALS; N-BI2SE3; SELENIDE; ALLOYS; STATES

Abstract

V originále

We have investigated the optical properties of thin films of topological insulators Bi2Te3, Bi2Se3, and their alloys Bi-2(Te1-x Se-x)(3) on BaF2 substrates by a combination of infrared ellipsometry and reflectivity in the energy range from 0.06 to 6.5 eV. For the onset of interband absorption in Bi2Se3, after the correction for the Burstein-Moss effect, we find the value of the direct band gap of 215 +/- 10 meV at 10 K. Our data support the picture that Bi2Se3 has a direct band gap located at the Gamma point in the Brillouin zone and that the valence band reaches up to the Dirac point and has the shape of a downward-oriented paraboloid, i.e., without a camel-back structure. In Bi2Te3, the onset of strong direct interband absorption at 10 K is at a similar energy of about 200 meV, with a weaker additional feature at about 170 meV. Our data support the recent GW band-structure calculations suggesting that the direct interband transition does not occur at the Gamma point but near the Z-F line of the Brillouin zone. In the Bi-2(Te1-x Se-x)(3) alloy, the energy of the onset of direct interband transitions exhibits a maximum near x = 0.3 (i.e., the composition of Bi2Te2Se), suggesting that the crossover of the direct interband transitions between the two points in the Brillouin zone occurs close to this composition.

Links

LM2015041, research and development project

Name: CEITEC Nano

Investor: Ministry of Education, Youth and Sports of the CR

692034, interní kód MU

Name: TWINFUSYON - Twinning for Improving Capacity of Research in Multifunctional Nanosystems for Optronic Biosensing (Acronym: TWINFUSYON)

Investor: European Union, Spreading excellence and widening participation

Files attached

PhysRevB.96.235202.pdf

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Citovat

DUBROKA, Adam, Ondřej CAHA, Miloš HRONČEK, Pavel FRIŠ, Milan ORLITA, Václav HOLÝ, H. STEINER, Günther BAUER, Günter SPRINGHOLZ and Josef HUMLÍČEK. Interband absorption edge in the topological insulators Bi-2(Te1-xSex)(3). Physical Review B. College PK, MD USA: AMER PHYSICAL SOC, 2017, vol. 96, No 23, p. "235202-1"-"235202-10", 10 pp. ISSN 2469-9950. Available from: https://dx.doi.org/10.1103/PhysRevB.96.235202.

@article{1403957,
   author = {Dubroka, Adam and Caha, Ondřej and Hronček, Miloš and Friš, Pavel and Orlita, Milan and Holý, Václav and Steiner, H. and Bauer, Günther and Springholz, Günter and Humlíček, Josef},
   article_location = {College PK, MD USA},
   article_number = {23},
   doi = {http://dx.doi.org/10.1103/PhysRevB.96.235202},
   keywords = {BISMUTH TELLURIDE; BI2SE3; SURFACE; BI2TE3; CRYSTALS; N-BI2SE3; SELENIDE; ALLOYS; STATES},
   language = {eng},
   issn = {2469-9950},
   journal = {Physical Review B},
   title = {Interband absorption edge in the topological insulators Bi-2(Te1-xSex)(3)},
   volume = {96},
   year = {2017}
}

TY  - JOUR
ID  - 1403957
AU  - Dubroka, Adam - Caha, Ondřej - Hronček, Miloš - Friš, Pavel - Orlita, Milan - Holý, Václav - Steiner, H. - Bauer, Günther - Springholz, Günter - Humlíček, Josef
PY  - 2017
TI  - Interband absorption edge in the topological insulators Bi-2(Te1-xSex)(3)
JF  - Physical Review B
VL  - 96
IS  - 23
SP  - "235202-1"-"235202-10"
EP  - "235202-1"-"235202-10"
PB  - AMER PHYSICAL SOC
SN  - 24699950
KW  - BISMUTH TELLURIDE
KW  - BI2SE3
KW  - SURFACE
KW  - BI2TE3
KW  - CRYSTALS
KW  - N-BI2SE3
KW  - SELENIDE
KW  - ALLOYS
KW  - STATES
N2  - We have investigated the optical properties of thin films of topological insulators Bi2Te3, Bi2Se3, and their alloys Bi-2(Te1-x Se-x)(3) on BaF2 substrates by a combination of infrared ellipsometry and reflectivity in the energy range from 0.06 to 6.5 eV. For the onset of interband absorption in Bi2Se3, after the correction for the Burstein-Moss effect, we find the value of the direct band gap of 215 +/- 10 meV at 10 K. Our data support the picture that Bi2Se3 has a direct band gap located at the Gamma point in the Brillouin zone and that the valence band reaches up to the Dirac point and has the shape of a downward-oriented paraboloid, i.e., without a camel-back structure. In Bi2Te3, the onset of strong direct interband absorption at 10 K is at a similar energy of about 200 meV, with a weaker additional feature at about 170 meV. Our data support the recent GW band-structure calculations suggesting that the direct interband transition does not occur at the Gamma point but near the Z-F line of the Brillouin zone. In the Bi-2(Te1-x Se-x)(3) alloy, the energy of the onset of direct interband transitions exhibits a maximum near x = 0.3 (i.e., the composition of Bi2Te2Se), suggesting that the crossover of the direct interband transitions between the two points in the Brillouin zone occurs close to this composition.
ER  -

DUBROKA, Adam, Ondřej CAHA, Miloš HRONČEK, Pavel FRIŠ, Milan ORLITA, Václav HOLÝ, H. STEINER, Günther BAUER, Günter SPRINGHOLZ and Josef HUMLÍČEK. Interband absorption edge in the topological insulators Bi-2(Te1-xSex)(3). \textit{Physical Review B}. College PK, MD USA: AMER PHYSICAL SOC, 2017, vol.~96, No~23, p.~''235202-1''-''235202-10'', 10 pp. ISSN~2469-9950. Available from: https://dx.doi.org/10.1103/PhysRevB.96.235202.

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