Cluster-emission devices

Figure 32. Cluster emission device - proteins are insulators (band gap of 2 eV), electric breakdown at -500 V/pm, nano-cluster-enhanced breakdown at about 3-200 V.

Amine not only affects the fundamental optical gaps but also produces a significant enhancement of absorbance and fluorescence, as indicated by an enhancement in the oscillator strengths of the amine-capped SiQDs relative to the H-SiQDs. In small clusters, the Si-N bonds most likely act, at least, in two different ways (a) to reduce the optical gap and (b) to enhance the light absorption and emission. Amine is hydrophilic and the produced amine-capped surfaces are expected to be useful for solution phase sequential reactions with various aldehydes and carboxylic acids. Therefore, H2N-SiQDs may play an important role in fabricating hybrid devices and sensors. 

The EL properties of PVK multilayered EL devices doped with ZnS Mn and based on nanocrystalline particles were also investigated and compared with bulk thin film materials [271], The PVK double layer was fabricated by successive spincoating of PVK and PVK NCs, and the film thickness of each layer was about 100 nm. It was found that multilayer EL devices that exhibited luminance up to thousands of cdm [272] in the case of the application of nanocrystalline parhcles only reached a luminance of the order of 0.1cdm , probably due to an aggregation of nanoparticles. In turn, the properties of ZnSiPVK nanocomposites confined in the MCM-41 silicate were studied [273], To prepare PVK ZnS nanocomposites confined in the silicate, MCM-41 was modified with ethylenediamine followed by introduction of ZnS into their mesopores. Finally, N-vinylcarbazole was mixed with the obtained ZnS/MCM-41 and polymerized at 85°C for 6.5 h. In the PL spectra, an emission peak at 468 nm was observed. Further analysis indicated that the emission could be attributed to the exciplex of excited-state PVK molecules and ground-state ZnS clusters [272],... 

Marpe M, Heuser C, Diesing D, Wucher A (2011) Internal electron emission in metal-insulator-meted thin film tunnel devices bombarded with keV aigon tmd gold-cluster projectiles. Nucl Instrum Methods Phys Res, Sect B 269 972-976... 

---