THE BEHAVIOR OF DOPANT INCORPORATION AND INTERNAL STRAIN IN ALXGA1-XAS0.03SB0.97 GROWN BY MOLECULAR-BEAM EPITAXY

Electrical properties and donor ionization energy level E(D) in Te-dop ed n-AlxGa1-xAs0.003Sb0.97 (0 < x < 0.8) grown by MBE have been invest igated. The electron concentration of Te-doped AlGaAsSb was found to b e strongly affected by the Al composition and by the donor energy leve l E(D) for Te. E(D) takes the form of an inverted ''W'' with a maximum at the GAMMA-L direct-indirect band crossover and L-X crossover. The structural characteristics of the AlGaAsSb/GaAs have been studied by d ouble-crystal X-ray diffraction. Results show that the lattice misfit strain was not fully relaxed by the generation of mismatch dislocation s.