Electrical Transport Studies of Electro Optically Active Semiconductors Master’s Thesis Proposal...

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Electrical Transport Studies of Electro Optically Active Semiconductors Master’s Thesis Proposal Committee Members Dr.Terry Golding Dr. Roman Stemprok Dr. Mitty Plummer Presented By Srikala Kambhampati
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Transcript of Electrical Transport Studies of Electro Optically Active Semiconductors Master’s Thesis Proposal...

  • Electrical Transport Studies of Electro Optically Active SemiconductorsMasters Thesis Proposal Committee MembersDr.Terry GoldingDr. Roman StemprokDr. Mitty Plummer

    Presented By Srikala Kambhampati

  • OverviewMotivationBackground Work to be performedSample PreparationAnticipated ResultsAnticipated TimelineSummary

  • MotivationSilicides (-FeSi2 ) Urgent requirement for an optical emitter that is compatible with standard silicon based ultra large scale integration(ULSI) technology. III-V Semiconducting materials Engineering of existing III-V semiconductors such as GaAsSb.

  • Background Direct bandgap semiconductors are efficient for optical emission properties.

    Direct Bandgap transitionIndirect Bandgap transition

  • BackgroundSilicon Bulk silicon has an indirect energy bandgap and is therefore highly inefficient as light source.GaAsGaAs has a direct band gap.

  • Band StructureSilicon Band structureGaAs Band structure

  • Why -Fesi2?It exhibits quasi direct bandgap around 0.8eV corresponding to 1.5m wavelength.

  • -Fesi2 band structure

  • Light emission has been observed only in strained films of -Fesi2.An alternative to strain is band structure modification by alloying.-Fesi2

  • Crystal Structure of GaAsSb

  • Ordering in III-V Semiconductor alloys

  • Reduction in the Band Gap

  • Characterization techniquesElectrical Magneto transport technique.

    Optical Transmission measurements like absorption co-efficient and photoluminescence.Electro-Optical Photocurrent measurements.

  • Magneto Transport TechniqueHall Effect

    Hall effect sign conventions for p-type sampleHall effect sign conventions for n-type sample

  • Hall EffectHall Coefficient RH: RH =VHt/(BI)

    Conductivity: = I l/(VA )

    Mobility:= RH

  • Work To Be PerformedStudying the electrical characteristics of -Fesi2 as a function of different dosages and implantation energies of ions.

  • Work To Be PerformedExamining the anisotropic properties of GaAsSb as a function of the degree of ordering.

  • Sample Preparation SilicidesMolecular Beam Epitaxy by W.Henrion, Hahn-Meitner-Institut Berlin GmbH, Berlin, Federal Republic of Germany, A.G.Birdwell, University of Texas at Dallas, Texas, U.S.A, V.N.Antonov, Institute of Metal Physics National Academy of Sciences of Ukraine, Ukraine, Jepsen, Max-Planck-Institutf ur Festko rperforschung, Federal Republic of Germany.

    GaAsSb Molecular Beam Epitaxy at National Renewable Energy Laboratory by A.G.Norman.

  • Equipment AvailableElectrical characterizationHigh Field Cryostat.

    Sample HolderSample with contacts

  • Magnets used for Magneto Transport Characteristics Equipment Available

  • Anticipated ResultsThe electrical characteristics of -Fesi2 material will be studied for various dosages of ions and implantation energies.GaAsSb The Electrical anisotropic characteristics of the samples will be studied for the different degrees of ordering


  • Anticipated Timeline

  • SummaryThe proposed study of the semi conducting -Fesi2 and the anisotropic properties of GaAsSb are presented. The study of the opto electronic properties of these materials may be potentially useful in novel device applications.