ANTI-STOKES LUMINESCENCE IN NITROGEN-DOPED GAAS1-XPX ALLOYS

In indirect band gap GaAs1-xPx alloys, the Nx levels of the excitons b ound to nitrogen have been resonantly excited. The detection of the ph otoluminescence (PL) at energies greater than the excitation energy (A nti-Stokes Luminescence (ASL)) shows a new PL band which appears at te mperatures lower than 40 K. Its mean energy 2.205 eV is nearly indepen dent of the alloy composition. We investigate ASL as a function of exc itation photon energy, excitation power and temperature. Moreover ASL has been time resolved.