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The CSRL includes a vertically integrated effort in solid-state physics and
device research. This effort combines use of CSRL capabilities in materials and
process science and technology with solid-state physics theory and modeling to
enable novel devices with improved performance.
CSRL's theory and modeling activities include:
- Electromagnetic modeling of guided-wave photonic devices with beam
propagation techniques
- Self-consistent classical and quantum mechanical models that simultaneously
solve the Schrodinger and Poisson equations for heterostructures
- Carrier transport and recombination phenomena in heterostructures,
including those occurring at high fields and carrier densities
- Thermal transport in device structures laser theory and nonlinear optical
properties of semiconductors
- Band structure of new semiconductor compounds
Many of these models are combined into unified treatements of specific
device structures, such as VCSELs and FETs. In addition, an extensive suite of
commercial software packages is used for microwave circuit and device
simulation and for electromagnetic field calculations.
Microelectronic devices
Building on past innovations, such as the first strained quantum well
field-effect transistor (FET), some important current microelectronic device
efforts are:
- Wide-bandgap AlGaN / GaN high-electron mobility transistors (HEMTS) for microwave power amplifiers
- Devices based on self-aligned refractory gates, including complementary
heterojunction-field-effect transistors
(HFETs) and distributed FETs
- High-performance heterostructure bipolar transistor (HBT) photoreceivers in
InGaAs on InP and power switching electronics
- High-frequency InP HEMTs
Optoelectronic devices
Optoelectronic devices work on microcavity resonators has grown into a
major effort in vertical-cavity surface-emitting laser (VCSEL) technology
(shown below). Some key accomplishments and activities in this area
include:
- First visible wavelength VCSEL diodes, based on the AlInGaP materials
system
- Innovative infrared VCSEL designs for high (greater than 50%) efficiency
and low (submicroamp) threshold operation
- Integration of VCSELs and micro-optical elements for advanced systems
Continuing research is focused on developing new materials that will extend
emission wavelengths into the visible and mid-infrared wavelengths. Exploration
of advanced concepts in photonic lattices and nanostructured optical surfaces
may lead to new engineered photonic materials for future device activities.
Nanoelectronics and nanophotonics
Using CSRL's nanofabrication capabilities — including ultra-high-mobility
materials, direct-write electron-beam lithography and advanced dry etching
— advanced nanodevices concepts not yet realized in the commercial sector
are also being explored. These nanodevices include those with nanometer-scale
gates and air-bridged point contacts, and those with three-dimensional
nanometer-scale features, such as photonic lattices. They also include those,
such as quantum dots, that can be used to investigate solid-state physics
phenomena based on tunneling and low dimensionality.The long-range goal for
these efforts result is ultra-small and ultra-low-power devices that operate
with only a few electrons per device.
- Solid-state physics and device research
- Semiconductor materials and process science and technology
- Microelectronic and optoelectronic integrated circuits
- High-frequency communication systems development
- Semiconductor materials and process science and technology
- Solid-state physics and device research
- Microelectronic and optoelectronic integrated circuits
- High-frequency communication systems development
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