Related papers: Terahertz intersubband absorption in non-polar m-p…
By monitoring changes in excitonic photoluminescence (PL) that are induced by terahertz (THz) radiation, we observe resonant THz absorption by magnetoexcitons in GaAs/AlGaAs quantum wells. Changes in the PL spectrum are explored as a…
The temperature and strain dependences of the optical conductivity spectrum of hexagonal manganese telluride (MnTe) were measured, revealing absorption in the terahertz (THz) region from spin-split bands to acceptor levels. The temperature…
Magneto infra-red absorption measurements have been performed in a highly doped GaAs quantum well which has been lifted off and bonded to a silicon substrate, in order to study the resonant polaron interaction. It is found that the pinning…
The quality factors of modes in nearly identical GaAs and Al_{0.18}Ga_{0.82}As microdisks are tracked over three wavelength ranges centered at 980 nm, 1460 nm, and 1600 nm, with quality factors measured as high as 6.62x10^5 in the 1600-nm…
This paper assesses the effects of Ge-doping on the structural and optical (band-to-band and intersubband (ISB)) properties of GaN/AlGaN multi-quantum wells (QWs) designed to display ISB absorption in the short-wave, mid- and far-infrared…
A negative magnetoresistance under the in-plane magnetic field, reaching maximum 30-40% of its zero-field value in fields higher than ~12 T, has been found in wide Ge_{1-x}Si_x/Ge/p-Ge_{1-x}Si_x quantum wells (QW) containing the…
The cross-over from quasi-two- to quasi-one-dimensional electron transport subject to transverse electric fields and perpendicular magnetic fields are studied in the diffusive to quasiballistic and zero-field to quantum Hall regime.…
A holistic computational analysis is developed to calculate the quantum efficiency of InAs/GaSb superlattice-based photodetectors. Starting with the electronic band characteristics computed by taking the InSb/GaAs at the interface using the…
We theoretically study the effect of THz radiation on the linear optical absorption spectra of semiconductor structures. A general theoretical framework, based on non-equilibrium Green functions, is formulated, and applied to the…
We report on the design and demonstration of ultra-wide bandgap AlGaN polarization-graded field effect transistors with ultra-thin channels to enable excellent current density and high-frequency performance while significantly reducing…
InGaN/GaN multiple quantum wells (MQWs) have been studied by using cathodoluminescence hyperspectral imaging with high spatial resolution. Variations in peak emission energies and intensities across trench-like features and V-pits on the…
We study linear and non-linear coefficients of the intersubband absorption in InSb-based stepped quantum wells subjected to an in-plane magnetic field. We consider also a transverse electric field to achieve near resonance conditions.…
We have addressed the existing ambiguity regarding the effect of process-induced strain in the underlying GaN layer on AlGaN/GaN heterostructure properties. The bandgaps and offsets for AlGaN on strained GaN are first computed using a cubic…
We suggest to use InAs/GaSb coupled quantum wells for THz lasing. In these heterostructures THz lasing is based not on intersubband but on interband transitions. Crucial advantages of this design in comparison with intersubband lasers are…
We report on the analysis of electroabsorption in thin GaAs/Al$_{0.3}$Ga$_{0.7}$As nanophotonic waveguides with an embedded $p$-$i$-$n$ junction. By measuring the transmission through waveguides of different lengths, we derive the…
We report the design and demonstration of ultra-wide-bandgap (UWBG) AlGaN polarization-graded field-effect transistors (PolFETs) that achieve a current-gain cutoff frequency above 85 GHz and a current density exceeding 1.3 A/mm. Ultra-thin…
The effect of outdiffusion of Mn interstitials from (Ga,Mn)As epitaxial layers, caused by post-growth low-temperature annealing, on their electronic- and band-structure properties has been investigated by modulation photoreflectance (PR)…
Composite spectra derived from HST observations of moderate redshift (z~1) quasars show that the peak of the spectral energy distribution is at ~1000 A, and that the ionizing continuum falls off smoothly to shorter wavelengths as $f_\nu…
In this paper, a route to ultra-broadband absorption is suggested and demonstrated by a feasible design. The high absorption regime (absorption above 90%) for the suggested structure ranges from visible to mid-infrared (MIR), i.e. for the…
Quantum spin Hall insulators (QSHIs) based on HgTe and three-layer InAs/GaSb quantum wells (QWs) have comparable bulk band-gaps of about 10--18~meV. The former however features a band-gap vanishing with temperature, while the gap in…