Аннотация:Using time-domain spectroscopy we studied the
topological insulators, Bi2-xSbxTe3-ySey thin films of different
thickness and chemical composition. The obtained temporal
dependences of terahertz pulses show that generation of THz
radiation is more effective in an island film with a total thickness
of about tens of nanometers. For the first time amplification of
the THz radiation power by applying an external electric field to
a topological insulator is demonstrated. This effect can be useful
for fabricating photoconductive antennas based on topological
insulators.