Donor doping of Ga in ZnO varistor grain boundary

The effect of Ga doping on the grain boundary properties of a ZnO varistor has been presented in this note. Within the range of doping level studied, it is shown that Ga acts as a donor at the grain boundary and behaves similar to that of Al.¹ The grain boundary doping behavior of both Ga and Al, when acting as donors, can therefore be represented by the same defect model.