In this letter, we show efficient electrical spin injection into a SiGe based \textit{p-i-n} light emitting diode from the remanent state of a perpendicularly magnetized ferromagnetic contact. Electron spin injection is carried out through an alumina tunnel barrier from a Co/Pt thin film exhibiting a strong out-of-plane anisotropy. The electrons spin polarization is then analysed through the circular polarization of emitted light. All the light polarization measurements are performed without an external applied magnetic field \textit{i.e.} in remanent magnetic states. The light polarization as a function of the magnetic field closely traces the out-of-plane magnetization of the Co/Pt injector. We could achieve a circular polarization degree of the emitted light of 3 % at 5 K. Moreover this light polarization remains almost constant at least up to 200 K.
@article{arxiv.0901.2183,
title = {Spin injection in Silicon at zero magnetic field},
author = {L. Grenet and M. Jamet and P. Noé and V. Calvo and J. -M. Hartmann and L. E. Nistor and B. Rodmacq and S. Auffret and P. Warin and Y. Samson},
journal= {arXiv preprint arXiv:0901.2183},
year = {2009}
}