DETERMINATION OF NITROGEN-ACCEPTOR SPIN-HAMILTONIAN PARAMETERS IN ZNSE EPILAYERS VIA SPIN-FLIP RAMAN-SPECTROSCOPY

Resonant spin-flip Raman scattering measurements were performed for ni trogen-doped ZnSe grown on a (001)GaAs substrate by molecular-beam epi taxy. By tuning the excitation laser to resonance with the acceptor-bo und exciton transition, spin-flip Raman scattering was observed betwee n the spin states of the neutral nitrogen accepters split by an extern al magnetic field. The spin-flip transitions exhibited strong magnetoo ptical anisotropy depending on the orientation of the magnetic field B with respect to the growth axis. The strain-induced splitting Delta b etween the light-and heavy-hole states was found to play an important role in the interpretation of the spin-flip Raman spectra. Specimens i n which Delta is comparable to the Zeeman energies of the acceptor wer e chosen for study. In such specimens the parameters <(kappa)over tild e> and (q) over tilde the spin-Hamiltonian terms -<(kappa)over tilde>m u(B)J.B and -(q) over tilde mu(B)J(3).B for the nitrogen acceptor, tog ether with Delta itself, could be determined accurately by varying the field direction from [001] to [110] and, in the layer plane, from [11 0] via [010] to [110]. The experiments give <(kappa)over tilde> = -0.5 0 +/- 0.05 and (q) over tilde = -0.005 +/- 0.01 and also demonstrate t hat accurate determination of the strain splitting Delta is possible f or layers in which Delta is too small for the excitonic transitions in volving the Light-and heavy-hole states to be resolved by photolumines cence or by photoluminescence-excitation spectroscopy.