OPTICAL SPECTROSCOPY OF MBE GROWN ALGAAS GAAS QUANTUM-WELLS AT VARIOUS ACCEPTOR DOPING LEVELS/

An experimental study of the optical properties of acceptor-center dop ed quantum wells (QWs) is presented. We have studied the effects of ac ceptor doping at concentration levels varying from 10(16) up to 10(19) cm(-3) using steady-state photoluminescence (PL) and photoluminescenc e excitation (PLE). The quenching of excitons has been investigated by comparing the results obtained for n- and p-type bulk and QW structur es doped both in the well and in the barrier. At a doping concentratio n higher than 5 X 10(16) cm(-3), an additional excitonic component is observed on the low energy side of the principal neutral acceptor boun d exciton (BE). The second feature is associated with BEs formed by ex citons bound at interacting accepters. Additional information is obtai ned from temperature, excitation intensity dependence and time resolve d measurements. The effect of hydrogen passivation of the same samples is also studied. (C) 1997 Elsevier Science S.A.