Nanosecond dynamics in intrinsic topological insulator Bi2-xSbxSe3 revealed by time-resolved optical reflectivity

Article

关键词: SINGLE DIRAC CONE;    BI2SE3;    SPECTROSCOPY;    RELAXATION;    POINT;   

DOI  :  10.1103/PhysRevB.103.L020301

来源: SCIE

【 摘 要 】

Bi2Se3 is an ideal three-dimensional topological insulator in which the chemical potential can be brought into the bulk band gap with antimony doping. Here, we utilize ultrafast time-resolved transient reflectivity to characterize the photoexcited carrier decay in Bi2-xSbxSe3 nanoplatelets. We report a substantial slowing of the bulk carrier relaxation time in bulk-insulating Bi2-xSbxSe3 as compared to n-type bulk-metallic Bi2Se3 at low temperatures, which approaches 3.3 ns in the zero pump fluence limit. This long-lived decay is correlated across different fluences and antimony concentrations, revealing unique decay dynamics not present in n-type Bi2Se3, namely the slow bimolecular recombination of bulk carriers.

【 授权许可】

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