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.Základní údaje
Originální název
Interband absorption edge in the topological insulators Bi-2(Te1-xSex)(3)
Autoři
DUBROKA, Adam; Ondřej CAHA; Miloš HRONČEK; Pavel FRIŠ; Milan ORLITA; Václav HOLÝ; H. STEINER; Günther BAUER; Günter SPRINGHOLZ a Josef HUMLÍČEK
Vydání
Physical Review B, College PK, MD USA, AMER PHYSICAL SOC, 2017, 2469-9950
Další údaje
Jazyk
angličtina
Typ výsledku
Článek v odborném periodiku
Obor
10302 Condensed matter physics
Stát vydavatele
Spojené státy
Utajení
není předmětem státního či obchodního tajemství
Impakt faktor
Impact factor: 3.813
Označené pro přenos do RIV
Ano
Kód RIV
RIV/00216224:14310/17:00099464
Organizační jednotka
Přírodovědecká fakulta
UT WoS
EID Scopus
Klíčová slova anglicky
BISMUTH TELLURIDE; BI2SE3; SURFACE; BI2TE3; CRYSTALS; N-BI2SE3; SELENIDE; ALLOYS; STATES
Štítky
Příznaky
Mezinárodní význam, Recenzováno
Změněno: 25. 2. 2019 16:46, Mgr. Pavla Foltynová, Ph.D.
Anotace
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.
Návaznosti
| LM2015041, projekt VaV |
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| 692034, interní kód MU |
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