High-performance digital alloy n-B-n AlInAsSb extended short-wave infrared detector

This work presents an AlInAsSb-based digital alloy n-B-n extended short-wave infrared (eSWIR) detector grown by molecular beam epitaxy (MBE) on a GaSb substrate. The device achieves a 50% cutoff wavelength of ∼2.86 μm and a 100% cutoff wavelength of ∼3.5 μm at room temperature. The photodetector exhibited a specific detectivity (D^∗) of 2.47 × 10¹⁰ cm·Hz^1/2 ·W^-1 at 300 K (with peak responsivity at 2.61 μm) at a bias voltage of -0.1 V, which improved to 1.22 × 10¹² cm·Hz^1/2 ·W^-1 at 160 K (with peak responsivity at 2.68 μm). These results highlight the potential of AlInAsSb-based photodetectors for high sensitivity, low bias voltage operation, and compact infrared sensing systems.