Low frequency noise in p-InAsSbP/n-InAs infrared photodiodes

We report the first experimental study of low-frequency noise in p-InAsSbP/n-InAs infrared photodiodes. For forward bias, experiments have been carried out at 300 and 77 K, in the photovoltaic regime the measurements have been done at 300 K. At room temperature the current noise spectral density, SI, exhibits the ∼1/f frequency dependence. For low currents, I ≤ I0 ∼ 4 × 10−5 A, SI is proportional to I2, at higher currents this dependence changes to SI ∼ I. At 77 K the noise spectral density is significantly higher than at 300 K, and Lorentzian contributions to noise are observed. The current dependences of spectral noise density can be approximately described as SI ∼ I1.5 and show particularities suggesting the contribution of defects.