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Daniel Barton
Daniel Barton
Manager


Diane Gaylord
Diane L. Gaylord
Admin. Asst.


Resources


Solid-State Lighting

 

 

 

 

 

 

Departments

Semiconductor Material and Device Sciences

The Semiconductor Material and Device Sciences Department is pushing the forefront of semiconductor device physics in the areas of compound semiconductor devices and materials and nanotechnology.

The Department's key staff members have diverse research interests that cover both theoretical and applied semiconductor device physics that includes:

 

quantum wires

Quantum transport research focused on studies of low dimensional systems. Key aspects include interactions both between nanostructures and many-body interactions. For coupled quantum wires and dots, tunneling effects and coherent transport for quantum computing are being studied. In 2D systems, electron-hole bilayers for exciton condensation studies have been fabricated.


conductance voltage

Optical properties of nano-structures including exciton formation and energy transfer in coupled undoped semiconductor quantum-dot, quantum-wire, and quantum-well structures. Transport properties of nano-structures including electron transport in quantum wires and quantum wells and electron tunneling/drag between coupled wires and 2D wells.


ultraviolet

Optical spectroscopy of wide-bandgap semiconductors and the development of novel optoelectronic devices. These devices include deep ultraviolet AlGaN LEDs relevant to both fluorescence-based biological agent detection and photovoltaic-compatible water purification systems, as well as green InGaN LEDs for high-energy-efficiency solid-state lighting.


px-led

Nitride-based optoelectronic emitters in the UV, blue and green spectral regions for applications such as solid-state lighting, UV epoxy curing, chem/bio detection, and high-density optical storage. Research areas include the use of 2D and 3D photonic crystal structures to improve LED efficiency, development of nitride-based edge emitters and vertical-cavity surface-emitting lasers, and development of high-efficiency green and yellow LEDs based on high In content InGaN.


molecular beam epitaxy

Molecular Beam Epitaxy growth of As-based III-V materials for intersubband structures for infrared emitters and detectors and high-purity growth of high-mobility structures for basic studies of quantum transport. The group has one of only three growers in the world with the demonstrated capability to grow operating THz quantum cascade lasers.

Quantum-dot optical properties: Excitation-dependent quantum-dot optical properties are investigated using a many-body theory where collision effects are treated at the level of a non-Markovian quantum kinetic analysis.

Active photonic lattices: Theory of emission from a radiating source embedded in a photonic lattice is being developed. The theory considers a finite photonic lattice coupled to free space, and uses a fully quantized description of the radiating source and electromagnetic field.

Laser dynamics and chaos: A strong coupling theory of coupled lasers is combined with numerical techniques from bifurcation theory to study dynamical nonlinearities associated with the optical coupling of lasers.

Research on semiconductor defects, charge transport mechanisms in thin-film insulators and defective oxides as well as metallic transport in charge density wave materials and superconductors. Also, structural characterization of materials with x-ray scattering.


plasmon detector

Experimental investigations on high-frequency (microwave through terahertz) electrodynamic properties and potential applications of novel semiconductor devices, novel materials, and nanostructures. Current research projects include terahertz excitation of plasmon resonances in semiconductor quantum wells, investigation of the microwave-to-millimeter wave AC conductivity of carbon nanotubes and other nanowires, and quantum microwave response in semiconductor nanodevices such as quantum dots and point contacts.


measurements

Studies in strongly correlated two-dimensional electron/hole systems, and coupled nano-scale semiconductor structures (heterostructures, quantum wells, superlattices, and quantum dots). Emphasis is on quantum transport and photoluminescence measurements in high magnetic fields and low temperatures, and on the dynamic response at radio and microwave frequencies.



reciprocal space map


The use of x-ray diffraction, reciprocal-space mapping, x-ray reflectivity, and atomic-force microscopy to analyze the microstructure and nanostructure of epitaxial thin-film materials. Studies of stress, strain, composition, dislocations, fracture, atomic ordering, compositional instability, alloy phase separation, segregation, and surface morphology in GaN, AlGaN, InGaN, InGaAs, InAlAs, InGaP, SiGe and other compound-semiconductor heterostructures are of interest.

 

 

 

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