Binding energy of positively charged acceptors in germanium - a Green's function Monte Carlo calculation

Recent spectroscopic measurements in Ge reveal positively charged acceptors consisting of an extra hole bound to a double or triple acceptor. Using the effective-mass approximation and a pseudo-atom model which permits up to four holes in the 1s ground state, we calculate the binding energies of these positively charged acceptors by the Green's function Monte Carlo method. For double acceptors the results of the pseudo-atom model compare favorably with experiments, whereas for triple acceptors the differences are significant. © 1984.