FOURIER-TRANSFORM MAGNETOPHOTOLUMINESCENCE SPECTROSCOPY OF DONOR-BOUND EXCITONS IN GAAS

High-resolution Fourier-transform photoluminescence spectroscopy combined with the resonant photoexcitation technique was used to study in detail the Zeeman effect on excitons bound to the neutral donors in high purity epitaxial GaAs. The neutral donor g-factor depends on the magnetic-field intensity and orientation in agreement with the predictions of the five-level k.p theory. The neutral-donor excited-state energies measured in a range of magnetic field from 0 to 12 T are in an excellent agreement with appropriately scaled calculations for the hydrogen atom. The correspondence between transitions having the same initial state but having as a final state either the nuetral-donor ground state (principal transitions) or a neutral donor excited state (two electron satellites) was established using resonant excitation and was verified by the angular dependences of the peak energies. Linear and circular polarizations of the 2p-, 2p0, and 2p+ two-electron satellites are consistent with the assignment of zero angular momentum to the ground state of the donor-bound exciton and we show that the transition energies for these components can be calculated with a 0.03-meV accuracy over the range from 0 to 12 T.