A F Ioffe Physico-Technical Institute, St Petersburg, Russia.
J Phys Condens Matter. 2010 Nov 24;22(46):465804. doi: 10.1088/0953-8984/22/46/465804. Epub 2010 Nov 5.
We present a systematic theoretical study of spin-dependent recombination and its effect on optical orientation of photoelectron spins in semiconductors with deep paramagnetic centers. For this aim we generalize the Shockley-Read theory of recombination of electrons and holes through the deep centers with allowance for optically-induced spin polarization of free and bound electrons. Starting from consideration of defects with three charge states we turn to the two-charge-state model possessing nine parameters and show that it is compatible with available experimental data on undoped GaAsN alloys. In the weak- and strong-pumping limits, we derive simple analytic equations which are useful in prediction and interpretation of experimental results. Experimental and theoretical dependences of the spin-dependent recombination ratio and degree of photoluminescence circular polarization on the pumping intensity and the transverse magnetic field are compared and discussed.
我们对半导体中深顺磁中心的自旋相关复合及其对光电子自旋光学取向的影响进行了系统的理论研究。为此，我们通过考虑光诱导自由和束缚电子的自旋极化，对深中心电子和空穴的复合的 Shockley-Read 理论进行了推广。从考虑具有三种电荷态的缺陷出发，我们转向具有九个参数的两电荷态模型，并表明该模型与关于未掺杂 GaAsN 合金的现有实验数据是兼容的。在弱泵浦和强泵浦极限下，我们推导出了简单的解析方程，这些方程在预测和解释实验结果时非常有用。实验和理论上的自旋相关复合比和光致发光圆偏振度对泵浦强度和横向磁场的依赖关系进行了比较和讨论。
