^ Luminescence and Laser Studies in III-V Semiconductors N. Holonyak, Jr.,* J. Wierer, D. Kellogg National Science Foundation, ECS 82-00517
(In conjunction with the Department of Physics)
Heterojunctions in AlxGa1-xAs-GaAs and related materials are being examined. Quantum size effects have been observed and have led to single and multiple active layer quantum-well diode light emitters and lasers. Stimulated emission, absorption, disorder, alloy clustering, carrier scattering, phonon processes, tunneling effects, and impurity diffusion in these structures are being studied. Impurity-induced disordering and Al-bearing native oxides are being studied and used to form stripe-geometry lasers and more complicated array structures. Quantum well lasers have been operated in an external grating cavity in an extended wavelength range. Newer forms of quantum-well lasers have been realized, including native-oxide-defined lasers and waveguides.
^ Quantum-Well Heterostructures N. Holonyak, Jr.,* J. Wierer, D. Kellogg National Science Foundation, DMR 89-20538
(In cooperation with the Department of Physics and the Materials Research Laboratory)
The fundamental properties of III-V heterostructures grown by vapor phase epitaxy are being studied. On quantum-well MOCVD AlGaAs-GaAs heterostructures, laser operation 400 meV above Eg(GaAs) has been observed, the first cw 300 K laser operation has been achieved, laser operation on phonon-sidebands below the confined-particle states has been observed, and alloy disorder and clustering in quantum-well heterostructures have been identified. Impurity-induced disordering of quantum-well heterostructures and Al-bearing native oxides, that is, the native oxide of AlxGa1-xAs formed at 400° to 500°C with H2O + N2, are being examined via TEM and photoluminescence studies. This project is the first (1977) to realize p-n quantum-well lasers and to coin the name "QW lasers."
