Abstract
Low frequency forward current noise as well as the photocurrent noise are studied in InAsSbP/InAs double heterostructure (DH) photodiodes, in the frequency range 1–104 Hz. The photocurrent noise in DH photodiodes is significantly lower than in single heterostructure (SH) photodiodes. The forward current noise in a DH diode exhibiting the 1/f frequency dependence is also much lower than that in SH diodes. However, in some DH diodes, it is the generation-recombination mechanism that provides the dominant contribution to the forward current noise; in this case the noise level is significantly higher. At sufficiently high forward current densities, the noise decreases with current. The observed generation-recombination noise spectrum cannot be described within the conventional theory.