Related papers: Semiconductor-based selective emitter with sharp c…
We have investigated electromagnetically induced transparency in the spectrum of selective reflection at the interface of Rb atom vapors and a dielectric nanocell window. A nanocell with atomic vapor column thicknesses ranging from 150 to…
We report the first spectral reflectance of tungsten carbide (WC) as potential solar selective absorber. We developed an optical measurement system for visible to mid-infrared spectroscopy, covering the range of 0.1 to 2.5 eV, to evaluate…
We have combined DFT calculations with the Boltzmann semiclassical transport theory to investigate the effect of selective hydrogenation on the thermoelectric properties of tetra-penta-deca-hexagonal graphene (TPDH-gr), a recently proposed…
Thermophotovoltaic (TPV) energy conversion efficiency has recently surpassed 30%. The key behind such high efficiency is the inclusion of a highly efficient mirror in the rear of the TPV cell that turns back to the thermal emitter the…
Tellurium (Te) is an intrinsically p-type doped narrow bandgap semiconductor with excellent electrical conductivity and low thermal conductivity. Bulk trigonal Te has been theoretically predicted and experimentally demonstrated to be an…
The theoretical maximum efficiency of a solar cell is typically characterized by a detailed balance of optical absorption and emission for a semiconductor in the limit of unity radiative efficiency and an ideal step-function response for…
Here we report on Landau level spectroscopy of an epitaxially grown thin film of the topological insulator Sb2Te3, complemented by ellipsometry and magneto-transport measurements. The observed response suggests that Sb2Te3 is a direct-gap…
Germanium-on-Silicon (Ge-on-Si) is a promising, CMOS-compatible platform for integrated terahertz (THz) photonics, offering a low-cost alternative to III-V semiconductors. A primary challenge for Ge-based photoconductive antennas (PCAs),…
We study the blackbody spectrum from slabs of three-dimensional metallodielectric photonic crystals consisting of gold nanoparticles using an ab initio multiple-scattering method. The spectra are calculated for different photonic-crystal…
Although van der Waals (vdW) layered MoS2 shows the phase transformation from the semiconducting 2H-phase to the metallic 1T-phase through chemical lithium intercalation, vdW MoTe2 is thermodynamically reversible between the 2H- and…
We propose an on-chip CMOS compatible graphene plasmonic photodetector based on the photo-thermoelectric effect (PTE) that occurs across an entire homogeneous graphene channel. The proposed photodetector incorporates the long-range…
We demonstrate here an efficient THz source with low electrical power consumption. We have increased the maximum THz radiation power emitted from SI-GaAs based photoconductive emitters by two orders of magnitude. By irradiating the SI-GaAs…
In the present work, first-principles calculations based on the density functional theory (DFT), GW approximation and Bethe-Salpeter equation (BSE) are performed to study the electronic and optical properties of penta-graphene (PG)…
A novel design for a compact gamma-ray spectrometer is presented. The proposed system allows for spectroscopy of high-flux multi-MeV gamma-ray beams with MeV energy resolution in a compact design. In its basic configuration, the…
We show in theory and experiment that in periodically patterned spintronic THz emitters (STE), charge dynamics can modify the emission spectrum in a well-controlled way. Characterization of sub-wavelength patterned STE at frequencies up to…
Gallium phosphide (GaP) is an indirect bandgap semiconductor used widely in solid-state lighting. Despite numerous intriguing optical properties---including large $\chi^{(2)}$ and $\chi^{(3)}$ coefficients, a high refractive index ($>3$),…
Nonreciprocal thermal emitters that break Kirchhoff's law of thermal radiation promise exciting applications for thermal and energy applications. The design of the bandwidth and angular range of the nonreciprocal effect, which directly…
We demonstrate thin-film metamaterials with resonances in the mid-infrared wavelength range. Our structures are numerically modeled and experimentally characterized by reflection and angularly-resolved thermal emission spectroscopy. We…
Thermophotovoltaic (TPV) converters are capable of generating electrical energy from infrared radiation emitted by an emitter powered by waste heat or solar energy. Key performance metrics for TPV converters are power output density (POD),…
At Argonne National Laboratory, we are developing hard X-ray (2 to 20 keV) Transition Edge Sensor (TES) arrays for beamline science. The significantly improved energy resolution provided by superconducting detectors compared to…