Computational Materials and Devices | SRI International

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Computational Materials and Devices

SRI employs a combination of theoretical methods and computational modeling to study phenomena ranging from atomic structure calculations to performance and analysis of optical and semiconductor devices. More specifically, we have studied:

chart showing COMSOL simulated temperature distribution
COMSOL simulated temperature distribution in VO2 bolometer exposed to long wavelength Infrared radiation.
COMSOL simulated temperature distribution graphic
Metamaterial slab converts diverging wavefronts from the dipole antenna into collimated wavefronts; simulated with HFSS
  • Electronic structure of atoms, molecules, clusters, nanoparticles, and ordered lattices using first-principles methods, commercial (e.g., SIESTA, DMOL3) codes, and in-house linear combination of atomic orbitals (LCAO) and empirical pseudopotential-based tight-binding methods;

  • Properties of semiconductors, including electrical and spin transport, optical absorption, nonlinear optical transmission, carrier lifetimes, defect formation, spin relaxation, and diamagnetism using in-house codes

  • Disordered materials such as VOx, a-Si, polymers, nanoparticles-loaded binders for sensing, and energy storage applications using in-house codes

  • Metamaterials and photonic band gap structures for optical modulation, switching, laser threat warning, and counter-directed energy applications using a combination of commercial HFSS and COMSOL and in-house TMM codes

  • Optical antenna design and fabrication for coherent sensing of photons, laser threat warning, and thermal energy harvesting applications

  • Device and materials modeling for various applications including infrared (IR) sensing and imaging, spin-precession magnetic sensing, optical limiting, graphene-based spin transistors, high-speed and high-frequency applications, and room-temperature magnetic levitation.

Publications

The Department of Defense, DARPA, and U.S. Department of Energy Office of Sciences' Basic Energy Sciences have funded most of our work, which has resulted in an extensive list of publications. To obtain a copy of any publication, srinivasan.krishnamurthy [at] sri.com (email us).

 

Capabilities and Studies

Methods

  • First-principles methods to solving the Schrödinger equation as applied to atoms, molecules, cluster, nanoparticles, and ordered lattice

  • Empirical pseudopotential-based tight-binding methods to study absorption, transport, and lifetimes

  • First-principles methods to solving Maxwell equations to study light modulation and propagation

  • Solutions to Boltzmann, drift, continuity and rate equations as appropriate to study charge, spin, and light transport through media

Codes

  • Commercial or public-domain codes—DMOL3, SIESTA, HFSS, COMSOL, OptiLayer, and TMM

  • In-house codes for tight-binding bandstructures, optical linear and nonlinear absorption, charge and spin transport, carrier and spin lifetimes, magnetic properties, dielectric properties, and device performance

Materials

  • Molecules and clusters

  • Semiconductor elements, compounds, and alloys

  • Graphene and carbon nanotubes

  • Disordered a-Si, VOx, polymers

  • Metal and dielectric nanoparticles and nanoparticles-in-binder

  • Metal and all-dielectric metamaterials

Applications

  • Infrared sensing—both photon sensor and bolometer

  • Magnetic sensing

  • Optical limiting

  • Optical modulation and switching

  • Laser threat warning

  • Counter-directed energy

  • Room temperature magnetic levitation

  • Supercapacitor for high energy and power density

  • Graphene spin transistor

  • Thermoelectric

  • High-speed and high-frequency devices

  • Nanoelectron tunneling devices