The spin-dependent recombination (SDR) has been observed in GaAs_{1-x}N_{x} (x = 2.1, 2.7, 3.4%) at room temperature. It reveals itself in a decrease of the edge photoluminescence (PL) intensity by more than a factor of 3 when either the polarization of the exciting light is changed from circular to linear or the transverse magnetic field of ~300 gauss (G) is applied. The interband absorption of the circularly polarized light results in a spin polarization of conduction electrons, which reaches 35% with increasing the pump intensity. The effects observed are explained by dynamical polarization of deep paramagnetic centers and spin-dependent capture of conduction electrons by these centers. The PL depolarization in a transverse magnetic field (Hanle effect) allows us to estimate the electron spin relaxation time in the range of 1 ns. Theoretically, it has been concluded that, due to the SDR, this long time is controlled by slow spin relaxation of bound electrons. In all the three alloy samples, a positive sign of the bound-electron g-factor is determined experimentally from the direction of their mean spin rotation in the magnetic field.
@article{arxiv.cond-mat/0508222,
title = {Spin-dependent recombination in GaAsN alloys},
author = {V. K. Kalevich and E. L. Ivchenko and M. M. Afanasiev and A. Yu. Egorov and A. Yu. Shiryaev and V. M. Ustinov and B. Pal and Y. Masumoto},
journal= {arXiv preprint arXiv:cond-mat/0508222},
year = {2009}
}