Anisotropic photoluminescence behaviour of vertical AlGaAs structures grown on gratings

Effects of anodic oxide induced intermixing on the structural and optical properties of quantum wire structure grown on nonplanar GaAs substrate

“…Thus, Ga rich vertical quantum wells ͑VQWL͒ are formed in the AlGaAs alloys at the bottom of the V grooves. 20 This VQWL on the TEM image appears as a vertical dark band across from the bottom of V-groove to the surface. VQWL plays a important role in feeding carriers to the QWR, which is very important for laser operation.…”

Carrier quantum confinement in self-orderedAlxGa1−xAsV-groove quantum wells

“…1,2 These structures consist of Ga-rich, thin (Ͻ20 nm) ''vertical'' regions formed at the center of a ͓011͔ oriented groove, surrounded by higher band gap Al x Ga 1Ϫx As barriers. The effect of the growth conditions ͑temperature and reactor pressure͒ and Al nominal composition of the Al x Ga 1Ϫx As layer on the Ga segregation-and hence the vertical quantum well ͑VQW͒ potential depth and widthhas been studied.…”

“…The effect of the growth conditions ͑temperature and reactor pressure͒ and Al nominal composition of the Al x Ga 1Ϫx As layer on the Ga segregation-and hence the vertical quantum well ͑VQW͒ potential depth and widthhas been studied. [2][3][4] Low-pressure ͑LP͒ ͑20 mbars͒ growth was demonstrated to yield extremely narrow ͑a few nm wide͒ multiple-VQW's with well-defined features. 4 The distribution of Al composition across the VQW was evidenced by atomic force microscopy ͑AFM͒ with a limited ͑a few nm͒ spatial resolution.…”

Self organized growth of doped vertical quantum wells for normal incidence intersubband transitions

“…This technique originates from the developments of the growth of quantum wires on non planar substrates [5], and was described in detail in reference [6,7]. Two samples were grown, sample A containing Si doped VQWs, and sample B with undoped VQWs, as a reference sample.…”

“…1 shows a stain-etched cross section of typical VQWs. Due to different migration properties of the Ga and the Al atoms (or the respective reactant species) [6], vertical layers of Ga-rich AlGaAs are formed along the grooves of the grating. In consequence, narrow stripes of lower Al content are grown in the bottom of the grooves, which are sandwiched between higher Al concentration alloys.…”