Epitaxial Cd3As2 for RF Device Applications
Abstract
Experimentally investigate the potential of one of the most promising 3D Dirac semi-metals for potential device applications by refining and optimizing MBE growth of single crystal epitaxial films and fabricating in 2 and 3 - tenninal device stuctures to determine the electronic and photonic characteristics for applications. The underlying stategy of the research approach is to improve the MBE growth synchronously with the device development, with each stage of device characterization feeding back into the MBE optization. Initial materials research will focus on controlling the band structure of the epilayers. Point defects introduced during growth can cause the Fermi level to be above or below the Dirac points, which could destroy the linear energy dispersion. GaSb and lnSb buffer layers will be explored, with growth on GaAs or GaSb. Magneto transport studies will investigate the thickness and stain dependence of the band structure. Transport studies under an applied electric field will establish materials quality, density of states, and band gap characterization. Electrical measurements, in particular of carrier densities and mobilities, will guide materials parameter optimization. These studies will also provide a fundamental understanding of the scattering mechanisms (which are not presently well understood and are substantially different from those in semiconductors) as a function of materials quality, temperature, and Fenni level (unintentional doping). Hall and magnetoresistance measurements will be used to determine the dependence of mobility and carrier density of holes and electrons as a function of growth conditions, thickness, and gate voltage. Use AFM (electric force) or Kelvin probe microscopy to explore the work function of Cd3As2, which is poorly understood. The material properties will inform the design of3 tenninal devices. In addition, the development of gate dielectrics compatible with the Cd3As2, as well as buffer or isolation layers under the carrier channel, will be pursued.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jan 12, 2017
- Source ID
- W911NF1610280
Entities
People
- Robert York
Organizations
- Army Contracting Command
- United States Army
- University of California, Santa Barbara