Low frequency noise study on short wavelength HgCdTe photodiodes

Abstract

The current-voltage characteristics and the low frequency noise measured at 255 —293K are reported. The figures of merit increase from 45×103 t o 7×104Ωcm2 as the temperatures decreases. At low fre quencies the noise mainly cons ists of flicker noise and generation recombination (g-r) noise, while at high fr equencies thermal noise is the dominant component. The flicker noise current is proportional to the detector current at reverse bias, and the Hooge parameter αH of the device is (3—7)×10-4. In addition, the fluc tuation time co nstant τ of the g-r noise is extracted by fitting the curve of the low_freq uency noise. Therefore, the trap thermal activation energy of the deep level is obtained from the relation between τ and temperature.