Electron paramagnetic resonance and dynamic nuclear polarization of ~(29)Si nuclei in lithium-doped silicon

摘要

Electron paramagnetic resonance (EPR) and dynamic nuclear polarization (DNP) experiments with Li-doped FZ silicon wafers are reported. The Li related EPR spectrum of tetrahedral symmetry was detected clearly without external stress even at low temperatures (T<5K) implying that the Li electron spin-lattice relaxation time is much shorter than that of other shallow donors, e.g. phosphorus. The solid-effect was found to be responsible for the DNP and the polarization was enhanced by a factor of 87 at 3.2 K to reach 0.17%.