Résumé
We report the first experimental study of low-frequency noise in reverse biased P-InAsSbP/n-InAs infrared photodiodes at 300 K and 77 K. At room temperature, the current noise spectral density, SI, depends on frequency as 1/f over the entire current range and tends to the Nyquist noise when the frequency increases. At small reverse currents Irb ≤ 3.10-5 A, SI is proportional to Irb^2 ; at higher currents this dependence changes to SI~ Irb^4 . With temperature decrease down to 77 K, SI becomes proportional to Irb^0.5 , while the reverse current decreasesand the differential resistance grows by 4 orders of magnitude. The noise was also studied in the photovoltaic mode at 100 K, where SI is proportional to 2rb I . We conclude that at 100 K, the Nyquist noise is dominant and can be used for estimations of the specific detectivity of PInAsSbP/n-InAs diodes.