Terahertz spectroscopy of topological insulator Sb2Se3 and its ultrafast nonequilibrium carrier dynamics

Tuning the band structure of a topological insulator is of interest for developing electronic devices or superconducting devices. Here we report the strain-dependent results for Bi
₂
Se
₃
films of various thicknesses that are grown via a self-organized ordering process. From the UV photoemission/inverse photoemission spectroscopy (UPS/IPES) results, ab initio calculations and THz-TDS data, significant changes of the Fermi level and band gap were observed.