The electronic structure of a shallow acceptor and its bound exciton confined in GaAs/AlGaAs quantum wells

The exciton bound (BE) at the shallow Be acceptor confined in a narrow GaAsIAlGaAs quantum well (QW) has been investigated by means of selective photoluminescence (SPL) and PL excitation (PLE) experiments. For the shallow acceptor, several excited states have been observed as two-hole transition (THT) satellites of the BE. The heavy hole (hh)-like excited nS(T6) acceptor states dominate the satellite spectrum, but also the light hole (lh)-like excited 2S(T7) and the parity forbidden transition to the 2P312 excited state have been monitored in SPL spectra. When detecting a THT satellite, the lS(T6) hh-like acceptor ground state has been spectrally resolved from the lS(T7) Ih-like state in PLE spectra. Several BE states have been theoretically predicted and observed in PLE spectra with the J=5/2 state at lowest energy, like in bulk GaAs. The proposed interpretation of the acceptor hhand lh-states is confirmed by SPL and PLE experiments in the presence of an applied magnetic field and in polarized PLE measurements. An effective g-value for the acceptor BE recombination in varying degree of confinement is derived from these Zeeman measu~ments.