Low dark current density extended short-wavelength infrared superlattice photodetector with atomic layer deposited...

We report on a low dark current density P-B-i-N extended short-wavelength infrared photodetector with atomic layer deposited (ALD) A l ₂ O ₃ passivation based on a InAs/GaSb/AlSb superlattice. The dark current density of the A l ₂ O ₃ passivated device was reduced by 38% compared to the unpassivated device. The cutoff wavelength of the photodetector is 1.8 µm at 300 K. The photodetector exhibited a room-temperature (300 K) peak responsivity of 0.44 A/W at 1.52 µm, corresponding to a quantum efficiency of 35.8%. The photodetector exhibited a specific detectivity (D ^∗) of 1.08×10¹¹ c m⋅H z ^1/2/W with a low dark current density of 3.4×10^-5 A/c m ² under -50m v bias at 300 K. The low dark current density A l ₂ O ₃ passivated device is expected to be used in the fabrication of extended short-wavelength infrared focal plane arrays for imaging.