Raman Scattering at Shallow Acceptors in InP

Electronic Raman scattering was used to investigate excited states of shallow acceptors in Zn- and in Cd-doped p-type InP with acceptor concentrations in the range between 1016 cm−3 and 1018 cm−3. Well resolved transition lines were obtained for acceptor concentrations of about 1017 cm−3 (Zn-doped) and 5 × 1017 cm−3 (Cd-doped), at higher concentrations the levels merge into broad bands. A linear correlation between the normalized intensity of the electronic spectrum and the acceptor concentration was found. The measured acceptor energy levels were used to prove which sets of published Luttinger parameters γ1, γ2 and γ3 are compatible with our results