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Spin-dependent recombination in GaAsN alloys

V. K. Kalevich·E. L. Ivchenko·M. M. Afanasiev·A. Yu. Egorov·A. Yu. Shiryaev·V. M. Ustinov·B. Pal·Y. Masumoto
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Abstract

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.

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V. K. Kalevich, E. L. Ivchenko, M. M. Afanasiev, A. Yu. Egorov, A. Yu. Shiryaev, V. M. Ustinov, B. Pal, Y. Masumoto. 2005-08-09. Spin-dependent recombination in GaAsN alloys. https://doi.org/10.1134/1.2142877

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