SPIN-FLIP RAMAN-SPECTROSCOPY OF NITROGEN ACCEPTORS IN ZNSE LAYERS WITH DIFFERENT BIAXIAL STRAINS

Resonant spin-flip Raman scattering (SFR) was used to investigate syst ematically the effects of strain on the J = 3/2 spin states of nitroge n accepters in p-type ZnSe grown on GaAs. Specimens from several MBE a nd MOVPE sources were studied and, by choosing specimens with differen t thicknesses of ZnSe, the in-plane biaxial strain could be chosen to be tensile or compressive, according to the extent of relaxation. For large tensile or large compressive strain, the acceptor states that le ad to scattering are, respectively, the light-and heavy-hole states, w hich can be distinguished by the very different anisotropy of the corr esponding SFR signals as the direction of the magnetic field is altere d. The investigation also included specimens with a range of intermedi ate layer thicknesses for which the strain splitting of the hole state s is comparable with the Zeeman splitting. In this case the field-indu ced 1h/hh mixing is significant and the spectra are very sensitive to the exact value of the strain. The spin-Hamiltonian parameters <(kappa )over tilde>( = -0.50 +/- 0.05) and (q) over tilde(= -0.05 +/- 0.01) w ere determined accurately by using specimens with small strains. (C) 1 998 Elsevier Science B.V. All rights reserved.