10 likes | 196 Views
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.
E N D
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 (g=1.11)) • Deep donors (g=1.81) • Shallow acceptors (g=0.81) • 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 ZnSe:N, 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.