Impurities

Orbital Stark Effect in Donors

Objective:

  • Donor states coupled to surface confined states.
  • Study adiabatic ionization
  • Interpret single donor transport expt.
  • Identify As vs. P
  • Variation of valley-orbit from donor to interface

Approach:

  • Impurity close to interface with high Field
  • Molecular states of donor-interface systems
  • About 1.4 M atoms, solve for 20+ states
  • Lanczos solver to obtain eigenvalues
  • Utilize TB donor models (As vs. P)

Results / Impact:

  • Quantitative description of the ionization process
  • Donor-interface hybrid states
  • Donor depth and field identified from expt.
  • Donor Species Identified
  • Valley-orbit variation from donor to interface obtained.
  • Screening effects estimated

Group member involved: