Very long wavelength infrared type-II detectors operating at 80 K

Abstract

We report a demonstration of very long wavelength infrared detectors based on InAs/GaSb superlattices operating at T=80 K. Detector structures with excellent material quality were grown on an optimized GaSb buffer layer on GaAs semi-insulating substrates. Photoconductive devices with 50% cutoff wavelength of λc=17 μm showed a peak responsivity of about 100 mA/W at T=80 K. Devices with 50% cutoff wavelengths up to λc=22 μm were demonstrated at this temperature. Good uniformity was obtained over large areas even for the devices with very long cutoff wavelengths.

Overview of antimonide based III-V semiconductor epitaxial layers and their applications at the center for quantum devices

“…Figure 9.11 shows the relative spectral response of three samples grown at the center, middle, and the edge of a three inch block simultaneously. The 10% cutoff energy varied only about 5 meV from the center to the edge, showing excellent uniformity over a very large area [80].…”

MBE growth and characterization of type-II InAs/GaSb superlattices for mid-infrared detection

“…Besides, the effective band gap of the SL can be tailored not only in the MWIR, but also in the 8-12 mm long wavelength infrared region (LWIR) and beyond, by varying the thickness of the constituent materials, allowing multispectral operation. Superlattice infrared detectors using InAs/GaSb system [5][6][7][8] and InAs/GaInSb system [4,[9][10][11][12][13] have been investigated to demonstrate LWIR operation and very long wavelength infrared detection around 20 mm. Photodiodes using short period InAs/GaSb SL recently exhibited promising results [14] in the MWIR domain.…”

High-performance InAs/GaSb superlattice photodiodes for the very long wavelength infrared range

“…We have previously reported type-II photoconductive devices grown on GaAs substrate in the c ϭ12 m to c ϭ22 m range operating at 80 K. 7 Unlike HgCdTe, 8 these detectors showed an excellent energy gap uniformity over a three-inch wafer area which is important for imaging applications. In this letter, we report on a series of high performance photovoltaic type-II superlattice detectors which show the same excellent uniformity in the VLWIR range.…”