ESR-RESONANCES IN DOPED GAAS AND GAP

ESR-signals from GaP:Sn, GaP:Si and GaAs:Si, GaAs:Te are reported. GaP:Sn crystals give two Isotropie signals. The larger one of them with g-value 1.998 is attributed to bound donor electrons. No definite conclusion about the origin of the other line with g = 2.131 is presented. The system GaP:Si gave only one line with g = 1.985, which we also attribute to bound donor electrons. GaAs:Si and GaAs:Te give each one very broad isotropic signal with g = 2.07 and g = 2.06 respectively. These values do not agree with earlier measurements on GaAs. They also disagree with theoretical values for shallow donors obtained by application of Roth's formula for g-factors. It is concluded that these signals are not likely to come from shallow donor electrons. The problems of treating impurity-levels in GaAs and GaP within the effective mass formalism are discussed. It is pointed out that a calculation following the Koster-Slater-method might be valuable in those cases of relatively deep donors. © 1969.