Using a metal-oxide-semiconductor field effect transistor (MOSFET) structure with a high-quality CoFe/n^+Si contact, we systematically study spin injection and spin accumulation in a nondegenerated Si channel with a doping density of ~ 4.5*10^15cm^-3 at room temperature. By applying the gate voltage (V_G) to the channel, we obtain sufficient bias currents (I_Bias) for creating spin accumulation in the channel and observe clear spin-accumulation signals even at room temperature. Whereas the magnitude of the spin signals is enhanced by increasing I_Bias, it is reduced by increasing V_G interestingly. These features can be understood within the framework of the conventional spin diffusion model. As a result, a room-temperature spin injection technique for the nondegenerated Si channel without using insulating tunnel barriers is established, which indicates a technological progress for Si-based spintronic applications with gate electrodes.
@article{arxiv.1211.6825,
title = {Room-temperature detection of spin accumulation in silicon across Schottky tunnel barriers using a MOSFET structure},
author = {K. Hamaya and Y. Ando and K. Masaki and Y. Maeda and Y. Fujita and S. Yamada and K. Sawano and M. Miyao},
journal= {arXiv preprint arXiv:1211.6825},
year = {2013}
}