Higher performance long wavelength interband cascade photodetector compared with a PBπBN device

In this paper, we reported our design and experimental results of a two-stage long wavelength interband cascade infrared photodetector (ICIP). A 3 × 3 multiple quantum well relaxation region was proposed for long wavelength ICIP. The 50% cutoff wavelength was 11.6 μm at 80 K. The quantum efficiency (QE) of the ICIP was measured to be 24.5% at 8.5 μm. The dark current density at −0.05 V bias of the ICIP was measured to be 3.32  × 10−4 A/cm2 at 55 K, which is approximately 1/3 of a PBπBN superlattice detector. The peak detectivity of ICIP was measured to be 4.6 × 1010 cm·Hz1/2/W at 80 K and further raised to 3.6 × 1011cm·Hz1/2/W when the temperature decreased to 55 K. In comparing with the PBπBN superlattice device, the ICIP shows smaller shunt currents and tunneling currents at low temperatures.In this paper, we reported our design and experimental results of a two-stage long wavelength interband cascade infrared photodetector (ICIP). A 3 × 3 multiple quantum well relaxation region was proposed for long wavelength ICIP. The 50% cutoff wavelength was 11.6 μm at 80 K. The quantum efficiency (QE) of the ICIP was measured to be 24.5% at 8.5 μm. The dark current density at −0.05 V bias of the ICIP was measured to be 3.32  × 10−4 A/cm2 at 55 K, which is approximately 1/3 of a PBπBN superlattice detector. The peak detectivity of ICIP was measured to be 4.6 × 1010 cm·Hz1/2/W at 80 K and further raised to 3.6 × 1011cm·Hz1/2/W when the temperature decreased to 55 K. In comparing with the PBπBN superlattice device, the ICIP shows smaller shunt currents and tunneling currents at low temperatures.