Spinflip Raman scattering studies of Sbdoped ZnSe

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Spin-flip Raman scattering studies of Sb-doped
ZnSe J. J. DAVIES, D. WOLVERSON , G. N. ALIEV
, S. ZENG Department of Physics, University of
Bath, Bath BA2 7AY UK J. F. WANG and M
ISSHIKI Institute for Advanced Materials
Processing, Tohoku University, Sendai 980-8577,
Japan

• In ZnSe, nitrogen and phosphorus form shallow
  acceptors.
• Phosphorus can also lead to very deep acceptor
  states, as does arsenic.
• What does antimony do?

• Spin flip Raman spectra depend on laser energy
  and show three types of signal
• In each case the Raman shift is proportional to
  the magnetic field

• Bulk crystals of ZnSe were doped during growth
  with Sb
• The PL spectra show exciton features and
  donor-acceptor pair lines
• Spin-flip Raman scattering was observed with the
  laser in resonance with the exciton lines

• The signals are due to
• Shallow donors (g1.11))
• Deep donors (g1.81)
• Shallow acceptors (g0.81)

• Donor g-values in ZnSe thus form a monotonic
  sequence as a function of depth.
• Modelling of this behaviour presents an
  interesting theoretical challenge

• The acceptor depth of 70 meV compares with 110
  meV and 85 meV for N and P acceptors

• The formation of the deep donor provides a
  compensation mechanism which, as in ZnSeN, may
  severely hinder attempts at successful p-type
  doping

• From Haynes rule, the depth of the deep donor is
  estimated at 55 meV.
• From the donor-acceptor recombination spectra, a
  shallow acceptor at 70 meV is shown to be present.