Recombination of Electrons and Donors inn-Type Germanium

This paper describes a study of the recombination of electrons and donors in $n$-type germanium at helium temperatures. The excess electron density is obtained by means of low-temperature breakdown. Experimental results indicate that the recombination probability varies approximately with the inverse of the square of the temperature. Recombination light was detected. The origin of the disagreement of the present measurements with those published by S. H. Koenig is discussed, and evidence is given to explain the discrepancies between the two measurements. The magnitude of the recombination cross section appears to depend on the binding energy of the electrons to the donor impurities, but large errors that are present in the determination of $N_A$ are responsible for a large uncertainty in the absolute magnitude of the cross section. The cross sections vary from ${10}^{-12\mathrm{}}$ to ${10}^{-11\mathrm{}}$ ${\mathrm{cm}}^2$.