Quantum-well structures

D.S. Chemla, D.A.B. Miller, and P.W. Smith, Nonlinear Optical Properties of Multiple Quantum Well Structures for Optical Signal Processing... 

Multiple linear regression methods, 16 753 Multiple-lined landfills, 25 877 Multiple liquid-path plates, 8 764 Multiple quantum well structure (MQW), 14 844... 

Quantum Well Structures for Optical Signal Processing... 

R. Kalish and S. Charbonneau, Ion Implantation into Quantum-Well Structures... 

The quantitative determination of Ge in SiGe quantum well structures (Si Ge layers and interfaces)50 by SIMS is compared to low energy RBS. The thickness of the analyzed quantum well was about 12nm and it was situated at a depth of about 60 nm below the surface. The SIMS measurements were performed using an oxygen primary ion beam over an area of 350 x 350 xm2. 

GaAs, GaAlAs, and GaP based laser diodes are manufactured using the LPE, MOCVD, and molecular beam epitaxy (MBE) technologies (51). The short wavelength devices are used for compact disc (CD) players, whereas the long wavelength devices, mostly processed by MBE, are used in the communication field and in quantum well structures. 

Related to the quantum well structures, "quantum dot" materials, or size-quantized semiconductor particles, have also been recognized to have nonresonant properties that are attractive. A series of small (< 30 A) capped (thiophenolate) CdS clusters has recently been shown to... 

Figure 6 A scheme of the three possible resonances in OOTF. i) Global resonance (A). Very weak electron-vibration interaction is expected ii) Localized resonances or traps (B).Usually the LEPS experiments are not detecting electrons trapped in these resonances and they appear as a reduction in the transmission probability, iii) Quantum well structure (C). Here the electron is localized in one dimension, while it is delocalized in the other two dimensions. There is a significant electron-vibration coupling.

Figure 1.11 shows an experimental determination of the band alignment at the ZnO/(Zn,Mg)0 interface using optical spectroscopy of quantum well structures [100]. The data indicate that the larger band gap of (Zn,Mg)0 is... 

First successful ZnO device demonstrations as for example stable homo-and heteroepitaxial pn-junctions and LED structures, thin film scintillators, and quantum well structures with optical confinement, and oxide-based Bragg reflectors, and high-quality Schottky contacts are based on PLD grown thin films. Several techniques as for example the PLD in UHV conditions (laser MBE), and gradient and combinatorial PLD, and high-pressure PLD for nano-heterostructures show the innovative potential of the advanced growth technique PLD. 

FIGURE 2 Bright-field transmission electron micrograph of a GalnN/GaN multiple quantum well structure exhibiting V-defects [12],... 

The optical properties of GalnN/GaN quantum wells differ somewhat from the well-known behaviour of other III-V-based strained quantum well structures, partly due to the rather strong composition and well width fluctuations, possibly induced by a partial phase separation of InN and GaN. The even more dominant effect seems to be the piezoelectric field characteristic for strained wurtzite quantum wells, which strongly modifies the transition energies and the oscillator strengths. However, the relative influence of localisation and piezoelectric field effect is still subject to considerable controversy. 

Low-excitation, low-temperature experiments like photoluminescence or photoluminescence excitation spectroscopy tend to indicate a considerable influence of localisation effects on the optical properties of GakiN/GaN quantum wells. Under high-excitation conditions typical for lasing, however, it is clearly seen that lasing from GalnN/GaN quantum well structures is due to a free-carrier plasma. 

C3.1 UV, blue and green InGaN quantum well structure LEDs... 

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