Strain effects on bound exciton luminescence in epitaxial GaAs studied using a wafer bending technique

Wafer bending was used to achieve externally controlled biaxial and uniaxia l strains in high purity GaAs epilayers grown by MBE to study strain effect s on bound exciton luminescence. Behavior of the energy levels under [001] and [110] strains confirms the validity of the crystal-field scheme for the acceptor bound excitons. The ratio of the deformation potentials d/b = 2.4 +/- 0.1 was determined from the best fit to the experiment. Distinct anti- crossing under uniaxial stress of the two lowest energy levels was observed for the donor bound excitons. Component 3 of donor bound exciton luminesce nce, previously assigned to the state J = 1/2, splits under stress into a d oublet. The complex behavior of the energy levels under stress may require a revision of the existing models of the donor bound exciton in GaAs.