We have studied the effects of the proximity of a bare Al 0.3Ga0.7As surface on the luminescence of an underlying GaAs quantum well (QW) before and after hydrogenation. The mechanism which is affected by H is tunneling to surface states through the surface barrier. Its thickness was varied by wet etching from 60 to 350 Å. Our experiments reveal that the degradation of luminescence efficiency from the QW is dependent on the surface barrier thickness and the excitation energy used in the photoluminescence measurements. A complete recovery or even further enhancement of luminescence efficiency was observed in the near-surface QW after low-energy ion-beam hydrogenation, even at room temperature.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)