Low frequency noise of CdTe single crystals under light illumination

Abstract

Noise spectroscopy of CdTe radiation detector has been carried out. When the sample is illuminated, 1/f noise is generated in the bulk as well as on the surface as a result of charge carrier interactions and also of radiation fluctuations. Conditions for the light absorption to take place on the surface only can be adjusted by properly selecting the wavelength. When the sample is illuminated by the light with the photon energy lower than the band gap energy noise is generated in sample volume and GR noise can be observed. For illumination by light with energy higher than the band gap energy light is observed on the surface and then we have measured 1/f noise only. In this case the corresponding sources are located on the surface