High‐pressure studies of topological insulators Bi₂Se₃, Bi₂Te₃, and Sb₂Te₃

Abstract

are narrow bandgap semiconductors with tetradymite crystal structure (R-3m) which have been extensively studied along with their alloys due to their promising operation as thermoelectric materials in the temperature range between 300 and 500 K. Studies on these layered semiconductors have increased tremendously in the last years since they have been recently predicted and demonstrated to behave as 3D topological insulators. In particular, a number of high-pressure studies have been done in the recent years in these materials. In this work we summarize the main results of the high-pressure studies performed in this family of semiconductors to date. In particular, we review recent results that address the main characteristics of the pressure-induced electronic topological transition and structural phase transitions observed in this family of compounds. Future high-pressure studies to be performed on these 3D topological insulators are also commented.

Structural, vibrational, and electrical properties of 1T−TiTe2 under hydrostatic pressure: Experiments and theory

“…It is noteworthy that the similar pressure induced decrease in linewidth of E mode and Eg modes were observed in BiTeI and A2B3 (A=Bi, Sb and B= Te, Se and S) series compounds during the TQPT at 34 GPa and electronic topological transitions (ETT) at 34 GPa respectively. 14,46,49 In contrast, the A1g linewidth increases up to 8 GPa with significant anomalies at ~ 2 GPa and ~ 4 GPa, followed by a decrease up to 10.5 GPa with a discontinuity observed during the phase transition at ~ 8.0 GPa. After the structural transition, the decreasing trend in linewidth of A1g phonon mode could be due to decrease in electron-phonon coupling in the monoclinic C2/m phase.…”

“…Raman linewidth studies could provide the information about the phonon-phonon interactions and the excitation-phonon interactions such as electron-phonon, spin-phonon coupling existing in the system. [45][46][47][48][49] Therefore, we have carefully analyzed the FWHM of A1g and Eg modes and are shown in the Fig. 8.…”

Pressure-induced electronic topological transition in Sb2S3

“…[22][23][24][25][26] An ETT is an isostructural second order phase transition, no volume discontinuity and no change in Wyckoff positions are anticipated during this transition. 41 An ETT causes anomalous signature in mechanical, electrical and thermodynamic properties and it also affects vibrational properties. [41][42] Hence, we interpret the anomaly at around 4 GPa in Sb 2 S 3 can be due to a second order isostructural phase transition called ETT in comparison with similar transition observed in the metal chalcogenide A 2 B 3 series.…”

“…41 An ETT causes anomalous signature in mechanical, electrical and thermodynamic properties and it also affects vibrational properties. [41][42] Hence, we interpret the anomaly at around 4 GPa in Sb 2 S 3 can be due to a second order isostructural phase transition called ETT in comparison with similar transition observed in the metal chalcogenide A 2 B 3 series.…”

High Pressure Semiconductor Physics

“…Within the case materials of the HPSP15 conference one can still fi nd group-III nitrides and the discussion of remaining open questions concerning their electronic, vibrational as well as optical properties [1], but also carbon based nanomaterials such as fullerenes, carbon nanotubes and, very recently, graphene, or a new class of materials that behave as insulators in the bulk but conduct electrical current in the surface, so-called topological insulators [2]. Probing semiconductors at highly anisotropic strains is diffi cult due to the inherent limitations of the commonly used static compression methods to generate the hydrostatic pressure or uniaxial stress.…”