Zusammenfassung

The photothermal spectra of the shallow acceptor boron in high purity p-Ge has been investigated for various magnetic field strengths at low temperatures. A large number of lines observed at frequencies above the binding energy of boron are attributed to optical excitation of quasi-bound Coulomb states, which arise in a magnetic field below each Landau level. By comparison with calculated Landau level energies the final states of the observed transitions can be unambigously identified.