Dependence of the binding energy of the acceptor on its position in a GaAs/${\mathrm{Al}}_{\mathit{x}}$${\mathrm{Ga}}_{1\mathrm{-}\mathit{x}}$As quantum well

Transitions from the ground state, 1s, to the first excited state, 2s, of the Be acceptor confined in GaAs/${\mathrm{Al}}_{\mathit{x}}$${\mathrm{Ga}}_{1\mathrm{-}\mathit{x}}$As quantum wells (QW’s) have been observed via two independent spectroscopic techniques: (a) two-hole transition of the bound exciton (BE) observed in selective photoluminescence, and (b) resonant Raman scattering. The transition energy has been determined from such measurements for acceptors with positions varying from the center to the edge of the QW using δ-doped samples. The results obtained are found to agree well with recent theoretical calculations for acceptors close to the center but disagree when approaching the edge of the QW. The binding energy of the BE is found to decrease when the acceptor position shifts from the center, where the binding energy has its maximum value towards the minimum at the QW interface.