High-Performance Dual-Band InAs/GaSb Type-II Superlattice Infrared Detector Grown by MOCVD

A bias-selective mid-/long- wavelength dual-band infrared detector based on InAs/GaSb type-II superlattices grown by metal-organic chemical vapor deposition (MOCVD) has been demonstrated. The detector features a back-to-back nNP-PNn heterojunction structure with barrier layers designed in the middle of the device. The XRD measurement of the
$5~\mu \text{m}$
-thick detector exhibits an excellent material quality with multiple satellite peaks and a lattice-matching condition. At 77 K, the device demonstrates a clear bias selectivity, with dark currents of
$1.86 \times 10 ^{-6}$
A/cm2 at −0.1 V for the mid-wavelength infrared (MWIR) channel and
$1.43 \times 10 ^{-3}$
A/cm2 at 0.15 V for the long-wavelength infrared (LWIR) channel. Spectral measurement indicates the MWIR channel has a 50% cut-off of
$5.8~\mu \text{m}$
, a peak quantum efficiency (QE) of 45% and a peak specific detectivity (D
$\ast $
) of
$1.60 \times 10 ^{12}$
cm
$\cdot $
Hz
$^{\mathrm {1/2}}$
/W while the LWIR channel has a 50% cut-off of
$10.9~\mu \text{m}$
, a peak QE of 32% and a peak D
$\ast $
of
$1.36 \times 10 ^{11}$
cm
$\cdot $
Hz
$^{\mathrm {1/2}}$
/W.