We describe a long wavelength infrared detector where an InAs/GaSb superlattice absorber is surrounded by pair of electron-blocking and hole-blocking unipolar barriers. A 9.9 μm cutoff device without antireflection coating based on this complementary barrier design exhibits responsivity 1.5 A/W dark current density 0.99×10−5 A/cm2 at 77 K under 0.2 V bias. The reaches 300 background limited photodetection (BLIP) operation 87 K, with black-body BLIP D∗ value 1.1×1011 cm Hz1/2/W for f/2 optics

We describe a method for computing transmission coefficients multiband tight-binding band-structure models. In this method, the probability can be calculated simply by solving system of linear equations representing form Schro\ifmmode\ddot\else\textasciidieresis\fi{}dinger equation over finite region interest, with specially formulated boundary and inhomogeneous terms to account effects incoming outgoing plane-wave states. addition being efficient, simple implement, our is numerically stable...

We analyze and compare different aspects of InAs/InAsSb InAs/GaSb type-II superlattices for infrared detector applications argue that the former is most effective when implemented mid-wavelength detectors. then report results on an superlattice based high operating temperature barrier detector. At 150 K, 50% cutoff wavelength 5.37 μm, quantum efficiency at 4.5 μm ∼52% without anti-reflection coating, dark current density under −0.2 V bias × 10−5 A/cm2, dark-current-limited f/2 black-body...

Optical components based on metasurfaces (metalenses) offer an alternative methodology for microlens arrays. In particular, metalens arrays have the potential of being monolithically integrated with infrared focal plane (IR FPAs) to increase operating temperature and sensitivity latter. this work, we demonstrate a type transmissive that focuses incident light (λ = 3–5 μm) detector after propagating through substrate, i.e., solid-immersion focusing. The is fabricated by etching backside...

InAs/GaSb superlattices are studied in cross section by scanning tunneling microscopy and spectroscopy. Electron subbands 42 \AA{} thick InAs layers clearly resolved the spectra. Roughness of superlattice interfaces is quantitatively measured. Interfaces grown on GaSb found to be rougher, with different electronic properties, than those InAs, indicating some intermixing former case.

A systematic study of the conduction bands (001) GaAs/${\mathrm{Al}}_{\mathrm{x}}$${\mathrm{Ga}}_{1\mathrm{\ensuremath{-}}\mathrm{x}}$As and ${\mathrm{Al}}_{\mathrm{x}}$${\mathrm{Ga}}_{1\mathrm{\ensuremath{-}}\mathrm{x}}$As/AlAs superlattices using a one-band Wannier orbital model is presented. The parameters in are fitted to correctly describe lowest band bulk semiconductors over entire Brillouin zone, including correct effective masses. Using this model, we have examined dependence...

Views Icon Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Twitter Facebook Reddit LinkedIn Tools Reprints and Permissions Cite Search Site Citation L. Höglund, D. Z. Ting, A. Khoshakhlagh, Soibel, C. J. Hill, Fisher, S. Keo, Gunapala; Influence of radiative non-radiative recombination on the minority carrier lifetime in midwave infrared InAs/InAsSb superlattices. Appl. Phys. Lett. 25 November 2013; 103 (22): 221908. https://doi.org/10.1063/1.4835055...

In this work, we investigate the high temperature performance of mid-wavelength infrared InAsSb-AlAsSb nBn detectors with cut-off wavelengths near 4.5 μm. The quantum efficiency these devices is 35% without antireflection coatings and does not change in 77–325 K range, indicating potential for room operation. current generation shows an increase operational bias temperature, which attributed to a shift Fermi energy level absorber. Analysis device that can be further improved. dark stays...

The electrical properties of CdTe and Cd1−xZnxTe crystals grown under excess tellurium by a modified Bridgman technique are critically dependent on the zinc content. Below an x value 0.07, as-grown CdZnTe n type while, above this value, p type. origin shallow donor level at 0.01 eV below conduction band is most likely singly ionized Te antisites (Te Cd sites). deep 0.75 therefore doubly antisites. Based model, determined results compensation between donors acceptors vacancies. High...

We present a device concept for spintronic transistor based on the spin relaxation properties two-dimensional electron gas (2DEG). The design is very similar to that of Datta and Das transistor. However, our proposed works in diffusive regime rather than ballistic regime. This eases lithographical processing requirements. switching action achieved through biasing gate contact, which controls lifetime spins injected into 2DEG from ferromagnetic emitter, thus allowing traveling be either...

We have designed and fabricated an optimized long-wavelength/very-long wavelength two-color quantum well infrared photodetector (QWIP) device structure. The structure was grown on a 3-in semi-insulating GaAs substrate by molecular beam epitaxy (MBE). wafer processed into several 640/spl times/486 format monolithically integrated 8-9 14-15 /spl mu/m (or dual wavelength) QWIP focal plane arrays (FPAs). These FPAs were then hybridized to silicon CMOS readout multiplexers. A thinned (i.e.,...

Epitaxially grown self-assembled InAs-InGaAs-GaAs quantum dots (QDs) are exploited for the development of large-format long-wavelength infrared focal plane arrays (FPAs). The dot-in-a-well (DWELL) structures were experimentally shown to absorb both 45deg and normal incident light, therefore, a reflection grating structure was used enhance efficiency. devices exhibit peak responsivity out 8.1 mum, with detectivity reaching ~1times10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML"...

We present a theory of steady-state impact ionization in GaAs including realistic band structure and the electron-phonon interaction using field-theoretic scheme that goes beyond first order processes. The explains most known experimental high-field transport data for satisfactorily, except anisotropy rate measured by Pearsall. It is concluded this not connected to quantum effects influencing scattering probably caused transient phenomena at metallurgical junction samples used investigating rate.

We describe the concept of submonolayer quantum dot infrared photodetector (SML QDIP) and report experimental device results on long-wavelength detection. An SML QDIP structure was fabricated into megapixel focal plane arrays, which produced clear images up to 80 K. Detectors in showed a responsivity peak at 7.8 μm noise equivalent temperature difference 33 mK 70

There was a significant improvement in the performance of infrared nBn detectors utilizing InAs/InAsSb absorbers culminating development focal plane arrays (FPAs) with excellent operability (99.7%) and operating at temperature significantly higher than InSb FPAs. In this work, we demonstrated that these can operate very low dark current densities enabling their use applications low-to-medium level background illumination. We showed single pixel photodetectors cut-off wavelength 4.8 μm...

We explore band structure effects to help determine the suitability of n-type type-II superlattice (T2SL) absorbers for infrared detectors. It is often assumed that exceedingly large growth-direction band-edge curvature hole effective mass in long wavelength (LWIR) T2SL would lead low mobility and therefore detector collection quantum efficiency. computed thermally averaged conductivity show LWIR along growth direction can be orders magnitude smaller than corresponding mass. InAs/GaSb have...

We apply the D'yakonov-Perel' (DP) formalism to [111]-grown zinc blende quantum wells (QW's) compute spin lifetimes of electrons in two-dimensional electron gas. account for both bulk and structural inversion asymmetry (Rashba) effects. see that, under certain conditions, splitting vanishes first order $k$, which effectively suppresses DP relaxation mechanism all three components. predict extended as a result, giving rise possibility enhanced storage. also study [110]-grown QW's, where...

In the past decade, there has been active research on infrared detectors based intersubband transitions in self-assembled quantum dots (QDs). two years, at least four groups have independently demonstrated focal plane arrays this technology. paper, progress from first raster scanned image obtained with a QD detector to demonstration of 640 512 imager QDs is reviewed. particular, emphasis will be placed novel dots-in-a-well (DWELL) design, which represents hybrid between conventional...

We report focal plane array (FPA) results on a mid-wavelength InAs/InAsSb type-II strained layer superlattice (T2SLS) unipolar barrier infrared detector with cutoff wavelength of 5.4 μm. For 300 K background in the 3-5-μm band, f/2 aperture, an FPA operating at 150 exhibits mean noise equivalent differential temperature (NEDT) 18.5 mK, and NEDT operability 99.7%. The NEΔT distribution has width 8 no noticeable tail, indicating excellent uniformity. noise-equivalent irradiance is 9.1 × 10...