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.