Papers by Keyword: Quantum Effect

Abstract: In this article we have developed an analytical model for Tri-gate Metal Oxide Semiconductor Field Effect Transistor (TG MOSFET) including Quantum effects for High-k/Ge material. The Schrodinger–Poisson’s equation is used to develop the analytical Quantum model using Variational method. A mathematical expression for charge centroid is obtained and then an inversion charge model was developed with quantum effects by means of oxide capacitance for different channel thickness and gate oxide thickness. The compact model is shown to reproduce transfer characteristics, transconductance and C-V curves of Tri-gate MOSFETs using the model and is compared with the device for Si/SiO₂ material. The results of both the model are compared to the simulated results. The comparison shows the accuracy of the proposed model for the high-k and Ge material.

Abstract: Stable TiO₂ colloids composing of narrow size distrubuted anatase TiO₂ nanocrystals were prepared using quaternary ammonium hydroxide, such as Me₄NOH, Et₄NOH and Bu₄NOH, as catalyst. TEM and UV-Vis spectra measurements showed that the TiO₂ colloids are quite stable in air or under ultrasound irradiation and the size of the TiO₂ particles of the colloids can be tuned by changing the molar ratio of Titanium isopropoxide and the organic additive. The additive can be removed when the dried gel were calcined at 450°C for two hours, resulting in pure TiO₂ nanocrystal in anatase phase.

Abstract: ZnSe thin films were obtained through chemical bath deposition method. Structural and optical properties of as deposited and annealed samples were investigated by X-ray Diffraction and spectrophotometer. The as deposited thin films were in nanocrystalline, with lots of strain and a blue shift of optical band gap. After annealing, the crystal grain gained, the strain eased and optical band gap enlarged. And it suggested that annealing can ease the quantum effect of chemical bath deposited ZnSe thin films.

Abstract: Quantum effects in nanostructured magnetic solid state materials open the new ways for preparing the novel electromagnetic devices with unique characteristics. At the same the electron spin based quantum effects are fully determined of formation and growing properties of molecular clusters of these solid state materials which are united in plane and volume structures also according their quantum (elementary particle interactions) properties.

Abstract: In this study, block copolymers of PS-b-PMSMA with various molecular weight were synthesized by atom transfer radical polymerization (ATRP). GPC analysis showed that the molecular weight distribution of the prepared PS-b-PMSMA could be controlled to be lower than 1.3 for the case of molecular weight less than 30,000. The chemical structures of the amphiphilic block copolymers of PS-b-PMSMA were well identified by FTIR. SEM showed that the spherical micelles and compound micelles were produced in hybrid films. The EDX analysis indicated that the nano-sized CdS particles have been successfully prepared in the PS-b-PMSMA composite films. The diameter of CdS particles calculated from Brus formula was about 4-5 nm. PL analysis revealed that the λmax of emission of the prepared composite materials had a red-shift as the CdS particle size increased.

Abstract: Scanning tunneling microscopy (STM) proved the existence of quasi-compounds on solid surfaces. A typical example is (-Ag-O-) or (-Cu-O-) chains grown on Ag(110) or Cu(110) surface by exposing to O2. The (-Ag-O-) chains on a Ag(110) reacts with Cu atoms to form a new quasi-compound of (-Cu-O-) chains on the Ag(110) surface. The (-Cu-O-) on the Ag(110) readily decomposes at ca. 570ºK to form Cu6 dots, and a reversible reaction of (Cu2)3 + O2. ↔ (-Cu-O-) takes place by exposing to O2. Deposited Zn, Sn and Ag atoms on a Si(111)-7x7 surface stabilize by forming Zn3, Sn2 and Sn, and Ag in a half unit cell. Layer-by-layer growth of Zn3 clusters occurs in a half unit cell, which results in the growth of a semi-conductive honeycomb layer of Zn3 clusters on the Si(111)-7x7 surface. By prohibiting hopping migration of Ag atoms on the Si(111)-7x7 surface by the adsorption of C2H5OH, nano-size Ag dots grow layer-by-layer in a limited mold spacing. The band gap of Ag-dots becomes narrower and narrower and becomes metallic at higher than 6 layers.