Photoconductive terahertz antennas based on topological insulators Bi2−xSbxTe3−ySey

The paper presents the results of a study of terahertz radiating antennas made on the base of island films of topological insulators of bismuth and antimony chalcogenides. It has been shown experimentally that a topological insulator film only a few tens of nanometers thick can generate terahertz radiation at the level of semiconductor films an order of magnitude thicker. Spectral and temporal characteristics of the emitted pulses are obtained. The mechanisms of relaxation of hot electrons, which determine the efficiency of generation of terahertz radiation in topological insulators, are discussed.