Excited states of the Zn and C acceptors inAl0.47Ga0.53As

Six excited states of Zn and of a shallow acceptor $X$ in the semiconducting alloy ${\mathrm{Al}}_{0.47}$ ${\mathrm{Ga}}_{0.53}$As have been determined by means of the selective pair luminescence technique. Their binding energies are compared with the effective-mass theory of Baldereschi and Lipari. For Zn the agreement is only qualitative. The central-cell correction amounts to 14.5 meV. Quantitative agreement is obtained for the shallow acceptor $X$ (no central-cell correction), provided that the Kohn-Luttinger valence-band parameters are slightly adapted: ${\gamma }_1=4.68\mathrm{}$, ${\gamma }_2=1.29\mathrm{}$, ${\gamma }_3=1.87\mathrm{}$, and $R_0=23.6\mathrm{}$ meV. Most probably, $X$ has to be identified with carbon.