Bulk and surface band structure of the new family of semiconductors BiTeX (X=I, Br, Cl)

Abstract

a b s t r a c tWe present an overview of the new family of semiconductors BiTeX (X = I, Br, Cl) from the perspective of angle resolved photoemission spectroscopy. The strong band bending occurring at the surface potentially endows them with a large flexibility, as they are capable of hosting both hole and electron conduction, and can be modified by inclusion or adsorption of foreign atoms. In addition, their trigonal crystal structure lacks a center of symmetry and allows for both bulk and surface spin-split bands at the Fermi level. We elucidate analogies and differences among the three materials, also in the light of recent theoretical and experimental work.

Structural, vibrational, and electrical study of compressed BiTeBr

“…This is in good agreement with the reported difficulty of exfoliating layers in bismuth tellurohalides [26,54]. This behavior can be understood if we consider that layers in bismuth tellurohalides are asymmetric (Te-Bi-Br) while in the other two families they are symmetric (Se-Bi-Se-Bi-Se or Se-In-In-Se).…”

“…Our measurements of the full width at half maximum of this Raman mode in BiTeBr (see Fig. S4 in [46]) also shows the same behavior but it was interpreted as due to its particular morphology of the two-phonon density of states and the way the frequency of the first-order mode sweeps the two-phonon density of states as pressure increases [54].…”

“…This behavior can be understood if we consider that layers in bismuth tellurohalides are asymmetric (Te-Bi-Br) while in the other two families they are symmetric (Se-Bi-Se-Bi-Se or Se-In-In-Se). The asymmetric layer in bismuth tellurohalides results in asymmetric charges in the layer [26,54]. The different electric charge in the Te plane than in the Br plane could contribute to a partially ionic character of the interlayer forces, which is not present in the other two families of layered materials, so that the interlayer forces are stronger in the bismuth tellurohalides than in other layered semiconductor families with symmetrical layers.…”

Termination-dependent surface properties in the giant-Rashba semiconductorsBiTeX(X=Cl, Br, I)

“…The narrow-gap semiconductors BiTeX (X = Cl, Br, I) have attracted considerable interest because of large Rashba-type spin-orbit splittings in their bulk and surface electronic structures [1][2][3], which have been observed by angle-resolved photoelectron spectroscopy (ARPES) [4][5][6][7][8] and magnetotransport measurements [9,10]. The enhanced spin-splitting in these materials is driven by their non-centrosymmetric crystal structure in combination with strong atomic spin-orbit coupling and a negative crystal-field splitting of the topmost valence bands [11].…”

Optical, electronic, and elastic properties of some A5B6C7ferroelectrics (A=Sb, Bi; B=S, Se; C=I, Br, Cl): First principle calculation

“…Fiedler et al [9] investigated the surface structural and electronic properties of the semiconductors BiTeX (X D Cl, Br, I) using the various techniques. Moreschiniet et al [16] investigated the surface states using the QUANTUM-ESPRESSO package. Dubeyet et al [17] observed that SbTeI showed metallic behavior from 4 K to 300 K and semiconducting behavior at higher temperature (>300 K).…”