Superlattice structure

Oonishi, T., Sato, S., Yao, H. and Kimura, K. (2007) Three-dimensional gold nanopartide superlattices Structures and optical absorption characteristics. Journal of Applied Physics, 101, 114314. 

Lead nitrate complexed with EDTA and lead perchlorate and sodium sulphide have been used for PbS ECALE-deposition.158159 The films were cubic and highly (200) oriented, and AFM images showed the same cubic structure.158159 PbSe films were also cubic, and the band gap of a film after 50 deposition cycles was 8000cm-1.160 PbSe/PbTe superlattices, with 4.2-nm and 7.0-nm periods, have been grown by ECALE.161 The (111) reflection in the XRD pattern showed a first-order satellite peak and one second-order peak, indicating the formation of the superlattice. AFM images of the superlattice structure showed a small amount of three-dimensional growth.161... 

Vossmeyer, T. Reck, G. Schulz, B. Katsikas, L. Weller, H. 1995. Double-layer superlattice structure built up of Cd32Si4(SCH2CH(0H)CH3)364H20 clusters. J. Am. Chem. Soc. 117 12881-12882. 

Gudiksen, M. S. Lauhon, L. J. Wang, J. Smith, D. Lieber, C. M. 2002. Growth of nanowire superlattice structures for nanoscale photonics and electronics. Nature 415 617-620. 

Figure 6.10 (a) Real-space superlattice structure and (b) the corresponding structure in... 

Device engineers and crystal growers are concerned with determining the following parameters of a superlattice structure ... 

Thin epitaxial layers display a rich variety of X-ray optical phenomena which can be exploited for materials characterisation. Superlattice structures in... 

Monolayers of alkyl chains on silicon are a significant addition to the family of SAMs. An ability to directly connect organic materials to silicon allows a direct coupling between organic materials and semiconductors. The fine control of superlattice structures provided by the self-assembly technique offers a route for building organic thin films with, for example, electrooptic properties on silicon. 

In order to solve the problems of the low solubility of magnetic ions in III-V semiconductors and the difficulty of the carrier control in II-VI semiconductors, modulation-doped III-V/II-VI superlattice structures have been proposed (Kamatani and Akai 2001a). Here, a... 

In case (iii), a blend with /PSJ = 1 -/PS-2 = 0.8 and 6 — 1.2 was examined (Koizumi el al. 1994c). For this asymmetric blend macrophase separation precedes microphase separation. A TEM image from a 30 70 blend is shown in Fig. 6.29. The continuous macrodomains consist of PI spheres in a matrix of PS, whereas the isolated domains contain PS cylinders dispersed in a matrix of PI. This was termed a superlattice structure, since two types of microphase-separated lattices coexist. 

Many quite different approaches to alleviating the miserable light emission in bulk Si ( 10 4 quantum efficiency at 300 K) have been proposed and are actively being explored.9"14 Some, such as Si i xGex quantum well or Si/Ge superlattice structures, rely on band structure engineering, while others rely on quantum confinement effects in low dimensional structures, as typified by quantum dots or porous Si (rc-Si15). Still another approach is impurity-mediated luminescence from, for example, isoelectronic substitution or by the addition of rare earth ions. An overview of results obtained with some of these methods is given below. However, in order to understand more fully the reasons why such different approaches are necessary, it is appropriate to review first what creates the optical emission problem in crystalline Si (c-Si). 

As the structure of a nanoparticle assembly depends mostly on interparticle interactions, the shape of a particle will alter such interactions and affect the position of the nanoparticles in a superlattice structure. HRTEM analysis on all nm Co nanoparticle assembly shows that the particles in the assembly have three different types of shapes square-like, hexagon-like and square [45]. Evaporation of the hexane solvent from the dispersion results in an assembly that is different from the spherical ones. These different shapes break the normal six-fold symmetry in a typical hep superlattice assembly, resulting in two popular defects, twins and stacking faults. 

As mentioned in the preceding section the mobility of degenerately-doped zinc oxide (as well as of other TCO materials and semiconductors) is limited by ionized impurity scattering in homogeneously-doped materials. Since about 30 years it is well known that the mobility can be increased by the so-called modulation doping method, introduced by Dingle et al. [179] for GaAs/C.ai, Af As superlattice structures (for a review see [180]). 

A high-quality GalnN/GaN MQW heterostructure was successfully fabricated by MOVPE. The fine superlattice structure was directly detected using TEM and SIMS analysis. The MQW greatly enhanced the optical efficiency in non-doped MQWs compared with the bulk GalnN layer. Consequently, the GalnN/GaN MQW is promising for die active layers of LEDs and LDs. 

Rama Venkatasubramanian, Phonon Blocking Electron Transmitting Superlattice Structures as Advanced Thin Film Thermoelectric Materials G. Chen, Phonon Transport in Low-Dimensional Structures... 

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