Co-doping of n-type and p-type impurities was investigated in uniformly or δ-doped structures by using Si and Be as the dopants. In highly Si-doped layers, the electrical activation ratio of Si donors was much less than unity because of the formation of compensating centres such as SiAs, Si clusters and VGa. It was found that most of these compensating centres disappeared as a result of co-doping; regardless of the doping structure. The integrated photoluminescence intensity of co-doped layers was much higher than that of Si-doped samples; thus indicating a reduction in non-radiative recombination centres.

Characteristics of Si and Be δ-Codoped GaAs Grown by MBE. S.Yonekubo, D.Ichiryu, Y.Horikoshi: Journal of Crystal Growth, 2001, 227-228, 88-92