The dark current of Quantum Well Inter-subband Photodetectors is affected by 1/f noise that limits the detectivity.
This paper applies for the first time conventional quantum 1/f noise expressions to calculate the expected level of 1/f
noise in QWIPs and applies the resulting engineering formulas to the case of GaInAs/InP and GaN/AlGaN QWIPs.
Both the collisionless and collision-dominated cases are considered. The elementary process causing the dark
current is the transfer of an electron from one well to the neighboring well. This happens under the influence of the
applied electric field, and has in general both thermally activated and tunneling components. The larger the applied
electric field, the larger is the squared velocity change of the carriers, and the larger is the obtained conventional
quantum 1/f effect. The detectivity of the devices is calculated on this basis. Quantum well intersubband
photodetectors (QWIPs) can be extended in principle from infrared into the THz region.