Design of mid-infrared InAs/GaSb superlattice detectors for room temperature operation

This paper presents the simulation of mid-infrared InAs/GaSb superlattice (SL) detectors by using a finite element FEMLAB code, which is a practical and useful tool to characterize and to define microelectronic devices with appropriate geometry. In the framework of this FEMLAB code, the electro-optic performances of the SL photodetectors for room temperature (RT) operation are theoretical evaluated in terms of zero-bias resistance-area product R 0 A and of external quantum efficiency η in order to estimate the specific detectivity D * . In the case of realistic SL active zone, calculated results show an optimal active zone thickness of about 1.3 μ m and a RT specific detectivity D λ * = 2 × 10 9 cm W - 1 Hz 1 / 2 at λ = 4 μ m . This expected value demonstrates that InAs/GaSb SL detector is a competitive technology suitable for third generation detectors.