Performance analysis of an N-structure type-II superlattice photodetector for long wavelength infrared applications

We propose a high performance N-structure type-II superlattice (T2SL) photodetector for long wavelength infrared (LWIR) applications. Theoretical study on the electrical and optical properties of the N-structure T2SL LWIR detector with different carrier concentration and different thicknesses in the p-region is carried out. We obtain the relationship of material parameters and performance parameters. With the increasing of the thickness of p-region, quantum efficiency (QE) gradually improves. In contrast, zero-bias resistance area (R0A) product decreases. QE will significantly decreases when the carrier concentration of p-region is too high, while R0A first increases, then decreases. The results show that the performance of the N-structure T2SL LWIR detector can be state of the art by optimizing the carrier concentration and material thickness during the structure growth and device fabrication.