Room temperature low frequency noise in n+-InAs/n-InAsSbP/InAs/p-InAsSbP double heterostructure infrared photodiodes

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.