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The emission properties of the Er-doped Si nanoclusters embedded in Si[O.sub.2] (NCSO) prepared by magnetron sputtering on different substrates are analyzed. The observed behavior indicates that the excitation mechanism of the 1.16 micro m photoluminescence (PL) is similar to that shown for Er-doped Si nanoclusters embedded in a Si[O.sub.2] matrix.

The structural and optical properties of MBE-grown GaAsSb/GaAs multiple quantum wells (MQWs) as well as strain-compensated GaAsSb/GaAs/GaAsP MQWs are investigated. The results of double crystal X-ray diffraction and reciprocal space mapping show that when strain-compensated layers are introduced, the interface quality of QW structure is remarkably improved, and the MQW structure containing GaAsSb layers with a high Sb composition can be coherently grown. Due to the influence of inserted GaAsP layers on the energy band and carrier distribution of QWs, the optical properties of GaAsSb/GaAs/GaAsP MQWs display a lot of features mainly characteristic of type-I QWs despite the type-II GaAsSb/GaAs interfaces exist in the structure. [Copyright &y& Elsevier]

High-indium-content InxGa1-xAs/GaAs single/multi-quantum well (SQW/MQW) structures have been systematically investigated. By optimizing the molecular-beam epitaxy growth conditions, the critical thickness of the strained In0.475Ga0.525As/GaAs QWs is raised to 7 nm, which is much higher than the value given by the Matthews and Blakeslee model. The good crystalline quality of the strained InGaAs/GaAs MQWs is proved by x-ray rocking curves. Photoluminescence measurements show that an emission wavelength of 1.25 μm at room temperatures with narrower full width at half maximum less than 30 meV can be obtained. The strain relaxation mechanism is discussed using the Matthews–Blakeslee model. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Solid-state tellurium (Te) is used as an n-type dopant of AlInP grown by molecular beam epitaxy (MBE). The carrier concentration proportionally increases with increasing Te beam equivalent pressure (BEP) up to a high doping density of 1×10 19 cm −3 . The incorporation of Te into AlInP results in a mirror-like surface at a moderate doping density due to its surfactant effect, while the surface roughness increased with a further rising of Te doping concentration. Furthermore, for the same In and Al flux ratio, the increase of the Te flux leads to a decreased In-content, but little effect on the alloy׳s disorder is observed. The highly Te-doped AlInP was used in a GaAs solar cell as a window layer. As compared with the solar cell with the Si-doped AlInP window layer, the device with the Te-doped AlInP window layer exhibits the higher efficiency and an extended increase under concentrated solar illumination, due to the benefits of the higher doping density in the Te-doped epilayer. [ABSTRACT FROM AUTHOR]

Abstract: Erbium-doped hydrogenated amorphous silicon suboxide films containing silicon clusters (a-SiO x :H) were prepared. The samples exhibited photoluminescence (PL) peaks at around 750nm and 1.54μm, which could be assigned to the electron–hole recombination in silicon clusters and the intra-4f transition in Er3+, respectively. We compared annealing behaviors of Si clusters and Er3+ emission and found that Si clusters emission depends strongly upon crystallinity of Si clusters, whereas Er3+ emission is not sensitive to whether it is Si nanocrystals (nc-Si) or amorphous Si (a-Si) clusters. The erbium-doped a-SiO x :H films containing either a-Si clusters or nc-Si have the same kind of Er3+-emitting centers. Based on these results, it is concluded that a-Si clusters can play the same role on Er3+ excitation as nc-Si. [Copyright &y& Elsevier]

Zn1−xMnxSe thin films with different Mn compositions are grown by metal-organic chemical vapor deposition on GaAs substrate. Good crystallinity of sample is evidenced by X-ray diffraction and rocking-curve measurements. Photoluminescence (PL) properties were carefully studied. A dominant PL peak close to the band edge is observed at low temperature for samples with higher Mn concentration. The temperature-dependent PL and time-resolved photoluminescence show that this emission peak is associated with the recombination of exciton bound to Mn-induced impurity bound states. It is found that rapid thermal annealing can induce reorganization of Mn composition in alloys and significantly reduce the density of impurity induced by Mn incorporation and improve the intrinsic interband transition. [Copyright &y& Elsevier]