The Influence of Defects on the Absorption of Terahertz Radiation in a CdSiP 2 Single Crystal

The transmission and reflection spectra of a CdSiP 2 single crystal are measured in the temperature interval from 80 to 300 K using the terahertz (THz) pulsed and infrared Fourier spectroscopy methods. A significant influence of postgrowth defects on the absorption in the THz frequency range is revealed. This absorption is found to depend weakly on temperature compared to that observed previously for other chalcopyrite crystal with substantially lower concentration of defects. Upon cooling, intrinsic absorption mechanisms are minimized, and the contribution of defects to absorption is separated.