STRUCTURAL AND OPTICAL STUDIES OF INXGA1-XAS GAAS MULTIPLE-QUANTUM WELLS/

Strained multiple quantum wells of In(x)Gal(1-x)As/GaAs were grown by low pressure metalorganic chemical vapor deposition (LP-MOCVD) and cha racterized by secondary ion mass spectrometry, x-ray diffraction, and optical spectroscopy. The structural analysis demonstrates the excelle nt control of the interface morphology and composition achieved by MOC VD growth. Temperature dependent optical absorption, photoluminescence , and magnetotransmission were used to evaluate the well-width depende nce of the major excitonic properties. The samples show sharp excitoni c resonances with distinct excited states evolving into Landau-type ex cited states in high magnetic field. The well-width dependence of the excitonic eigenstates and of the exciton binding energy as well reprod uced by envelope function and variational calculations, also in the pr esence of external electric field. Finally, nonlinear electro-optic mo dulation induced by the quantum confined Stark effect is demonstrated in a Schottky diode with extremely low switching threshold. (C) 1996 A merican Institute of Physics.