Low-Frequency Noises and DLTS Studies in HgCdTe MWIR Photodiodes

摘要

Both low-frequency noises and electrically active defects have been investigated for two technological variants, i.e. optimized and non-optimized, of the HgCdTe p on n technology applied to the mid-wave infrared blue band with a cut-off wavelength of 4.2 mu m. This has been achieved using electro-optical characterizations and the deep level transient spectroscopy (DLTS) technique. The results show that the impact of extra 1/f and random telegraph signal noises has been reduced with the optimization of the technology. Furthermore, a broadened DLTS peak, probably related to dislocations in the material, has been found for both variants, the relative amplitude of which is reduced in the optimized case. The potential correlation between low-frequency noises and this broadened peak is discussed.