Proposal for strained type II superlattice infrared detectors

Abstract

We show that strained type II superlattices made of InAs-Ga1−xInxSb x∼0.4 have favorable optical properties for infrared detection. By adjusting the layer thicknesses and the alloy composition, a wide range of wavelengths can be reached. Optical absorption calculations for a case where λc∼10 μm show that near threshold the absorption is as good as for the HgCdTe alloy with the same band gap. The electron effective mass is nearly isotropic and equal to 0.04 m. This effective mass should give favorable electrical properties, such as small diode tunneling currents and good mobilities and diffusion lengths.

Epitaxial growth of GaSb and InAs fins on 300 mm Si (001) by aspect ratio trapping

“…Moreover, InAs and GaSb are thought to be promising candidates to replace Si in sub-7 nm Complementary Metal-Oxide-Semiconductor (CMOS) devices due to their respective high electron and hole mobilities [5][6][7][8]. In addition to low voltage operation transistors, 6.1 Å family compound semiconductors are of great interest for near-and mid-infrared optoelectronic devices [9,10], and are considered very attractive for the fabrication of several building blocks required to develop silicon photonic platforms.…”

“N” structure for type-II superlattice photodetectors

“…3 Despite different performance levels, recent demonstration of SWIR, MWIR, and LWIR operation shows the flexibility of the superlattice material system 4 opening the way multiple band detectors. MWIR InAs/GaSb superlattice photodiode focal plane arrays (FPAs) operating at 77 K have already been demonstrated.…”

Confocal Raman spectroscopy and AFM for evaluation of sidewalls in type II superlattice FPAs

“…The strain in the InAs/GaSb T2SL system facilitates suppression of interband tunneling 29 and Auger recombination. 8 The larger effective mass (∼ 0.04 m • ) in T2SL leads to a reduction of tunneling currents compared with MCT detectors of the same bandgap.…”

“…8 The larger effective mass (∼ 0.04 m • ) in T2SL leads to a reduction of tunneling currents compared with MCT detectors of the same bandgap. 29 By optimizing the oscillator strength in this material system, a large quantum efficiency and responsivity can be obtained. Moreover, the commercial availability of substrates with good electro-optical homogeneity, and without large cluster defects, also offers advantages for T2SL technology.…”