Terahertz radiation from nonstoichiometric CuInSe_2 films excited by femtosecond laser pulses

摘要

We report on the observation of efficient terahertz radiation from the surface of CuInSe_2 excited by femtosecond laser pulses. Terahertz radiation emitted by polycrystalline CuInSe_2 layers manufactured by using electrodeposition technology was as powerful as the signals radiated by single-crystalline semiconductor surfaces. It has been found that terahertz radiation efficiency is critically dependent on the stoichiometry of the CuInSe_2 layers. The results of a double-pulse excitation experiment have indicated that terahertz radiation from the photoexcited surfaces of CuInSe_2 samples was caused by the presence of a built-in electrical field at those surfaces.