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 Lidoped FZ silicon wafers are reported. The Li related EPR spectrum of tetrahedral symmetry was detected clearly without external stress even at low temperatures (T<5 K) implying that the Li electron spinlattice relaxation time is much shorter than that of other shallow donors, e.g. phosphorus. The solideffect 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%.