Multilayer heterostructures

As a conducting polymer, polyaniline has many electronics-related applications, such as rechargeable batteries (Tsutsumi et al. 1995), multilayer heterostructure light-emitting diode devices (Onoda Yoshino 1995), biosensors (Bartlett Whitaker 1987), elec-trochromic windows (Nguyen Dao 1989), and nonlinear optical materials (Papacostadi-nou Theophilou 1991). Polyaniline may be prepared from aniline by both electrochemi-... 

The cnicial step of manufacturing gold LB gold junctions which can be cooled to 4.2 K has been achieved by a group from Stuttgart [24], They have observed rectification from multilayer heterostructures, and recorded what are believed to be... 

The other area of rapid progress is in the development of theories and computational tools with which to interpret spectroscopic results for rough surfaces, discontinuous layers and multilayered heterostructures. 

OPTICAL PROPERTIES OF MULTILAYER HETEROSTRUCTURES BASED ON ZnSe/ZnS... 

Self-Assembly Process. The ability to readily manipulate a wide variety of electroactive polymers at the nanoscale level makes it possible to create thin film heterostructures with optical and electrical properties that can be fine-tuned at the molecular level. As indicated earlier, we have demonstrated that this process can be utilized with many different conjugated, nonconjugated and electrically conductive polymers. Any variety of complex multilayer heterostructures can be fabricated with... 

We have previously shown that when PPV is self-assembled with specific electronically active polyanions such as poly(thiophene acetic acid) (PTAA) or sulfonated fiillerenes (S-C60 )(7), the photoluminescence of the PPV is essentially completely quenched by the polyanion. The mechanism of this quenching is believed to be due to a photoinduc electron transfer process taking place between the excited PPV and the adjacent electroactive polyanion molecules. The quenching process, in this case, is not associated with a Forster type energy transfer since in both cases, the required spectral overlap of a donor emission band with an acceptor absorption band is not fulfilled. In addition, photo-induced electron transfer processes have previously been confirmed in PPV/C60 systems and can be exploited to fabricate thin film photovoltaic devices (77). In order to mediate this electron transfer process, we have constructed multilayer heterostructures in which the PPV donor and the polyanion electron acceptor are separated from each other with electronically inert spacer layers of known thickness. In addition to allowing studies of the electron transfer process, such structures provide important insights into the thermal stability of the multilayer structure. The "spacers" used in this study were bilayers of SPS/PAH with an experimentally determined bilayer thickness of 30 +/-5 A. 

The future applications of 2D nanocrystals will be many and varied. It is possible to speculate over potential uses such as in electronic components and high performance nanocomposites. It is not, of course, necessary to use different individual types of 2D nanocrystals and hybrid systems have already been investigated. It is possible to create multilayer heterostructures and devices with designed electronic properties by stacking various 2D atomic nanocrystals crystals, such as graphene and boron nitride, on top of each other. These are essentially new forms of matter and the scope for developing hybrid systems is clearly vast and a whole host of unexpected applications of these novel materials will no doubt be forthcoming. 

Guo, X., Mantei, L, Jamnik, J., Lee, J.-S., and Maier, J. (2007) Defect chemical modeling of mesoscopic ion conduction in nanosized CaF2/BaF2 multilayer heterostructures. Phys. Reu. B, 76,125429. 

Sulfonated polyaniline has been used in the fabrication of multilayer heterostructures in light emitting diodes, the electrochemical control of electrolyte activity [238] and biosensors [239]. Recently,... 

A. C. Fou, O. Onitsuka, M. Ferreira, M. F. Rubner, B. R. FFseih, Interlayer interactions in self-assembled poly(phenylene vinylene) multilayer heterostructures, implications for light-emitting and photorectifying diodes, Materials Research Society Symposium Proceedings 1995, 575. 

Figure 12 Scheme of the structure of a virtual multilayered heterostructure made from all kinds of molecules or particles that have been shown to be usable for ESA. Components (a) boladications and other multipolar molecules (b) lipid bilayers (c) polyelectrolytes (d) dendrimers (e) DNA (p proteins (g) viruses (h) inorganic sheets (i) inorganic nanopartides (j) latex nanospheres (k) LB interlayers (I) biotin/avidin complex. (Adapted from Y.M. Lvov and G. Decher. Crystallogr. R p. 39 628,1994. With permission.)... 

In this contribution we introduce a new method for oiganic multilayered heterostructures deposition. Molecular Layer Epitaxy (MLE), that in a sense is widering the... 

However, while the sputtering technique is not very commonly used to study interlace effects in ionically conducting multilayer heterostructures, there are mmierous examples of thin film deposition. Actually, sputtering was the primary technique used for thin film deposition in the SOFC field, such as for Zr02 [84] and Ce02-based films [85]. The conducting properties were interpreted in terms of substrate-induced space charge effects, strain, or microstructure. 

Fig. 3 Compilation of oxygen ion conductivity data for multilayer heterostructures and epitaxial...

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