High-performance infrared photodetectors based on InAs/InAsSb/AlAsSb superlattice for 3.5†µm cutoff wavelength spectra.

High-performance infrared p-i-n photodetectors based on InAs/InAsSb/AlAsSb superlattices on GaSb substrate have been demonstrated at 300K. These photodetectors exhibit 50% and 100% cut-off wavelength of ∼3.2 µm and ∼3.5 µm, respectively. Under -130 mV bias voltage, the device exhibits a peak responsivity of 0.56 A/W, corresponding to a quantum efficiency (QE) of 28%. The dark current density at 0 mV and -130 mV bias voltage are 8.17 × 10-2 A/cm2 and 5.02 × 10-1 A/cm2, respectively. The device exhibits a saturated dark current shot noise limited specific detectivity (D*) of 3.43 × 109 cm·Hz1/2/W (at a peak responsivity of 2.5 µm) under -130 mV of applied bias.

Gradual funnel photon trapping enhanced InAs/GaSb type-II superlattice infrared detector.

InAs/GaSb type-II superlattice materials have attracted in the field of infrared detection due to their high quality, uniformity and stability. The performance of InAs/GaSb type-II superlattice detector is limited by dark noise and light response. This work reports a gradual funnel photon trapping (GFPT) structure enabling the light trapping in the T2SL detector absorption area. The GFPT detector exhibits an efficient broadband responsivity enhancement of 30% and a darker current noise reduction of 3 times. It has excellent passivated by atomic layer deposition and achieves a high detectivity of 1.51 × 1011 cm Hz1/2 at 78 K.