Influence of Magnetic Field on Blue Anti-Stokes Luminescence of ZnSe:Cr Crystals |
| V.Yu. Ivanov Department of Physics, University of Dnepropetrovsk, 320625, Dnepropetrovsk, Ukraine Yu.G. Semenov Institute of Semiconductors Physics, National Acad. of Science, 252650, Kiev, Ukraine M. Surma and M. Godlewski Institute of Physics, Polish Academy of Sciences, Al. Lotników 42/36, 02-668 Warsaw, Poland |
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| The results of photoluminescence and magneto-luminescence studies of chromium doped ZnSe crystals are presented for blue colour shallow donor-shallow acceptor pair photoluminescence, with a zero phonon line at 2.692 eV. This donor-acceptor pair photoluminescence is observed under photo-excitation with photon energies smaller than the emission energy (anti-Stokes luminescence) and dominates in the photoluminescence spectrum of ZnSe:Cr at the excitation energy about 2.41 eV and for temperature T<20 K. A quantum efficiency of this anti-Stokes luminescence is relatively large. It is of about 10-3 at 0 T and increases with increasing magnetic field up to 7 T at temperature T=2 K. We relate the intensity of the anti-Stokes luminescence to a non-equilibrium concentration of photo-excited Cr+ ions and propose that the rate of spin-dependent recombination of Cr+ ions with free holes (decreases with increasing magnetic field) is responsible for the observed increase in the anti-Stokes luminescence intensity at higher magnetic fields. |
| DOI: 10.12693/APhysPolA.90.821 PACS numbers: 71.55.Gs, 78.55.Et, 76.30.Fc |