RT info:eu-repo/semantics/article
T1 Temperature dependence of the Raman spectrum of orthorhombic Bi2Se3
A1 Serrano Gutiérrez, Jorge
A1 Jiménez López, Juan Ignacio
A1 Mediavilla Martínez, Irene
A1 Ayala, Paola
A1 Pichler, Thomas
A1 Kramberger, Christian
A1 Muñoz, Alfonso
A1 Manjón, Francisco Javier
A1 Rodríguez Hernández, Plácida
A1 Buga, Sergei
A1 Serebryanaya, Nadezhna
A1 Dadgostar, Shabnam
AB Bismuth selenide, a benchmark topological insulator, grows in a trigonal structure at ambient conditions and exhibits a number of enticing properties related to the formation of Dirac surface states. Besides this polytype, a metastable orthorhombic modification with Pnma space group has been produced by electrodeposition and high-pressure high-temperature synthesis displaying upon Sb doping significant thermoelectric properties in the midtemperature range. However, very little experimental information is available on the fundamental properties of this polytype, such as, e.g., the electronic band gap and the lattice dynamics. We report here the temperature dependence of the Raman spectra of orthorhombic Bi2Se3 between 10 K and 300 K, which displays an anharmonic behavior of the optical phonons that can be modelled with a two-phonon decay channel. In order to analyze the data we performed ab initio calculations of the electronic bandstructure, the phonon frequencies at the center of the Brillouin zone, and the phonon dispersion relations along the main symmetry directions, examining the effect of spin-orbit coupling in both phonon and electronic energies. Lastly, we report here cathodoluminescence experiments at 83 K that set a lower limit to the electronic bandgap at 0.835 eV, pointing to an indirect nature, in agreement with our calculations. These results shed light to essential properties of orthorhombic Bi2Se3 for further understanding of the potential of this semiconductor for thermoelectrics and new applications.
PB Universidad de Valladolid. Escuela de Ingenierías Industriales
YR 2004
FD 2004
LK https://uvadoc.uva.es/handle/10324/66302
UL https://uvadoc.uva.es/handle/10324/66302
LA eng
NO arXiv:2402.07256 [cond-mat.mtrl-sci]
DS UVaDOC
RD 22-nov-2024