Photoluminescence studies of bound excitons in copper-doped GaAs

The photoluminescence (pl) of copper-related bound excitons (BE’s) in GaAs is investigated by means of resonantly excited and time-resolved photoluminescence, as well as photoluminescence-excitation (ple) spectroscopy. Observation of the 2s and 3s two-hole transitions leads to a precise value of 193 meV for the hole binding energy of the acceptor associated with the F complex. No evidence for such two-hole transitions was ever detected for the C complex. The lifetimes of the C0 and the F0 BE’s are reported in addition to that of a line found at 1501.5 meV. C0 BE exhibit an excited state 3.7 meV above the ground state, while no excited states were detected for F0.