Determination of donor and acceptor densities in high-purity GaAs from photoluminescence analysis

We report a new analysis technique to determine the acceptor density NA and the donor density ND in high-purity GaAs from 10 K photoluminescence (PL) measurements. For both n-type and p-type samples, we find that NA/ND is related to the excitonic intensity ratio rx=I(A0,X)/I(D0,X) by NA/ND=0.89rx−0.06. In addition, NA can be determined from NA=1014IA, where IA is the emission intensity of the donor-acceptor pair transition normalized to the intensity of the unresolved exciton peak. Therefore, for n-type and p-type material with an impurity density 1013–1016 cm−3, NA and ND can be determined solely from a 10 K PL measurement. The advantage of this technique lies in its nondestructive nature and its applicability to situations where Hall measurements are not possible or suitable.