Bandfilling in metalorganic chemical vapor deposited AlxGa1−xAs-GaAs-AlxGa1−xAs quantum-well heterostructure lasers

Data are presented showing that quantum-well (Lz∼200 Å) AlxGa1−xAs-GaAs-AlxGa1−xAs heterostructures, grown by metalorganic chemical vapor deposition, can be operated as lasers on confined-particle transitions over an unusually large range (Δλ≳1000 Å). The bandfilling properties of these quantum-well heterostructures, which can easily be excited to carrier densities as high as n≳1019/cm3, are described. Quantum-well laser diodes (x∼0.5) are described that operate (300 K) from the Γ band edge to wavelengths as short as 7700 Å (ΔE∼185 meV). Narrow photopumped samples (15–30 μm) are shown to operate (77 K) as lasers on clearly defined confined-particle transitions from the band edge to 6980 Å (ΔE∼270 meV). On samples from another wafer, laser operation has been observed to 6885 Å (ΔE≡hν−Eg=293 meV). The photoluminescence spectra of these heterostructures extend well into the region of the recently determined L band minima of GaAs.