ULTRAFAST-LIFETIME QUANTUM-WELLS WITH SHARP EXCITON SPECTRA

Sharp quantum-confined excitons in semi-insulating low-temperature-growth AlAs/GaAs quantum wells with 15 ps carrier lifetimes are demonstrated. High-quality well-barrier interfaces can be grown at low substrate temperatures and annealed up to temperatures of 700°C, beyond which interface mixing broadens the exciton transitions. Electroabsorption from the quantum-confined Stark effect in as-grown p-i-n modulators approaches 10 000cm-1, which is comparable to traditional high-temperature growth quantum wells. The low-temperature growth quantum well structures eliminate the need for postgrowth processing, such as ion implantation for photorefractive quantum wells, ultrafast saturable absorption, or electro-optic sampling applications.© 1995 American Institute of Physics.