High-Performance InP-Based Bias-Tunable Near-Infrared/Extended-Short Wave Infrared Dual-Band Photodetectors

In this paper, a vertical stacked near-infrared (NIR) and extended short wavelength infrared (eSWIR) dual-band detector based on InGaAs and In _0.53 Ga _0.47 As/GaAs _0.5 Sb _0.5 type-II superlattice (T2SL) is presented. A barrier layer of AlAs _0.56 Sb _0.44 allows the independent working of the two sub-detectors. The InGaAs NIR sub-detector operates under positive bias, while the eSWIR band detector operates under reverse bias. The NIR sub-detector shows a dark current density of 7.35 × 10 ⁻⁵ A/cm ² under the bias of 0.1 V, the responsivity of 0.88 A/W, and a specific detectivity of 4.69 × 10 ¹¹ cm· Hz ^1/2 /W at 1510 nm. Meanwhile, the dark current density of eSWIR sub-detector is 8.68 × 10 ⁻⁴ A/cm ² under −0.4 V with the corresponding responsivity of 0.21 A/W, and a specific detectivity of 1.85×10 ¹⁰ cm·Hz ^1/2 /W at 2 μm. Furthermore, a single-pixel imaging system is built to demonstrate the capability of dual-band detectors in information capturing and target recognition.