Excitation Spectra of Lithium Donors in Silicon and Germanium

摘要: The excitation spectra of lithium in silicon and germanium have been measured. These exhibit lines which indicate that the excited states are similar to those Group-V impurities. For oxygen-free germanium, excitations observed occur at energies close transitions originate from upper ground these This indicates chemical splitting state may be very small. effect uniaxial stress on spectrum has examined. experimental results for interpreted as follows: site symmetry isolated is tetrahedral; an "inverted" Group-V-like state, $1s({A}_{1})$ lying 1.8\ifmmode\pm\else\textpm\fi{}0.1 meV above $1s(E+{T}_{1})$ state. oxygen-containing silicon, zero-stress uniaxialstress measurements with 7.7\ifmmode\pm\else\textpm\fi{}0.1 do not fit pattern.