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We have theoretically and experimentally demonstrated the feasibility of achieving ultra-low dark current in CpBnn type detectors based on a double-barrier InAs/GaSb/AlSb type-II superlattice. By employing a structure that separates the absorption region and depletion region, the diffusion, recombination, tunneling, and surface dark currents of the photodetector (PD) have been suppressed. Experimental validation has shown that a detector with a diameter of 500 µm at a bias voltage of −0.5 V exhibits a dark current density of 2.5 × 10−6 A/cm2 at the operating temperature of 300 K. The development of PD with low dark current has paved the way for applications with high demands for low noise in the fields of gravitational wave detection and astronomical observation. [ABSTRACT FROM AUTHOR]

We report a low dark current, high quantum efficiency nBn photodetectors based on In0.28Ga0.72As0.25Sb0.75 bulk materials with a cut-off wavelength of 3μm at room temperature. Generation-Recombination current was suppressed using an nBn design to shift deplete region from In0.28Ga0.72As0.25Sb0.75 active region into a wide band gap AlGaSb barrier region. The Arrhenius plots of R0A-1/T show that there is no Generation-Recombination current detected in nBn device, whereas pin devices have a Generation-Recombination dominant dark current at temperatures ranging from 160K to 220K. Optical characterizations at 300K show the nBn device using InGaAsSb as an absorption material has a relative high quantum efficiency. The nBn device exhibits a peak specific detectivity of 4.8×1010 Jones under 200mV reverse bias voltage at 300K. The low dark current, high quantum efficiency and band gap tunability are expected to make InGaAsSb bulk material a competitive candidate for short wavelength infrared regime. [ABSTRACT FROM AUTHOR]

We presented an extended-wavelength InGaAsSb infrared unipolar barrier detector working at room temperature. The detector with GaSb lattice-matched InGaAsSb absorb layer and AlGaAsSb unipolar barrier can achieve high material quality and low dark current. The dark current density was 2.29×10-5 A/cm2 at 0 bias at 77K. At room temperature the dark current at 0 bias was 4×10-3 A/cm2 and the R0A is high to 44 Ω · cm2. We fabricated the cone arrays in the InGaAsSb absorb layer to reduce the reflection of the radiation and extend the spectrum response to visible area. The extended-wavelength detector had the response from the wavelength of 0.4 μm. Further experiment showed the cone arrays also reduced the dark current of the detector at room temperature. [ABSTRACT FROM AUTHOR]

• We have manufactured a SWIR detector and characterized its photoelectric performance in detail. • We calculated the carrier lifetime and dark current activation energy of the device, and found that dark current limits its application at high temperatures. This study investigates the performance of infrared photodetectors through variable temperature tests, specifically examining dark current, light current, and capacitance. The reduction of dark current and the increase in carrier lifetimes are crucial for enabling the utilization of infrared photodetectors in complex environments. By conducting tests and analyses on high-performance detectors, the physical mechanisms governing carrier transport processes can be obtained. In order to elucidate the characteristics of InAs/GaSb/AlSb type-II superlattices, a short-wave infrared (SWIR) photodetector exhibiting low dark current and low saturation bias voltage is designed and fabricated. [ABSTRACT FROM AUTHOR]

The authors report an innovative design of wide spectrum detector that can detect visible and mid-infrared spectrum, from 0.4 to 5 μm, simultaneously. The detector is designed with microstructure of various types of photon traps fabricated on mid-infrared InAs/GaSb type-II superlattice materials. Quantum efficiency has been significantly improved due to the action of photon traps which can decrease the reflectivity of the surface of InAs/GaSb type-Ⅱ superlattice down to less than 5%. Under the condition of 77 K and 200 mV bias voltage, the responsivity of the detector is about 0.025–0.45 A/W in the visible wavelength regime of 400–790 nm, more than 0.3 A/W in spectrum of 800–2000 nm, respectively. Through the optimized photon trap structure, the responsivity of detector is to 1.25 A/W and predominantly improve the quantum efficiency of the detector up to 52.5% at 3 μm. [ABSTRACT FROM AUTHOR]