High-Performance InAs1-xSbx Detector Based on AlAs1-ySby/AlSb Quantum Tunneling Barrier

Barrier infrared photodetectors have been proposed to improve the device performance, such as the operating temperature. In this article, a quantum tunneling barrier with alternating AlAs0.08Sb0.92 and AlSb layers is adopted to enhance carrier extraction from an InAs0.91Sb0.09 (InAsSb) absorber layer (AL). Due to the small valence band offset between the AlSb and InAsSb layers, the photogenerated holes can be efficiently extracted by tunneling, despite the hole barrier between AlAs0.08Sb0.92 and InAsSb layers. The applied voltage of the detector with a tunneling barrier structure is reduced by about 31%, compared with that of a reference detector with an AlAs0.08Sb0.92 barrier, to fully extract the photogenerated holes. At 150 K, the quantum tunneling barrier detector exhibits a dark current density of ~
$4.35\times 10^{{-{5}}}$
A/cm2 and a quantum efficiency (QE) of 50.57% under 3.3-
$\mu \text{m}$
radiation corresponding to a responsivity of 1.34 A/W at a low bias voltage of −0.18 V. Due to the tunneling barrier, a peak specific detectivity as high as
$3.60\times 10^{{11}}$
cm
$\cdot $
Hz
$^{\text {1/2}}$
/W is achieved at a relatively low bias voltage of −0.14 V.