Solid State Phenomena Vols. 121-123

Abstract: Optimizing arithmetic primitives such as quantum-dot cellular automata (QCA) adders is important for investigating high-performance QCA computers in this emerging nano-technological paradigm. In this paper, we demonstrate that QCA ripple carry adder and bit-serial adder designs actually outperform carry-look-ahead and carry-select adder designs because of the increase in required interconnects. Simulation results obtained by using the QCADesigner tool for the proposed adder designs are also presented.

Abstract: Light emitting diode with MOS structures containing multiple-stacked Si quantum dots (QDs)/SiO2 was fabricated and the visible-infrared light emission was observed a room temperature when the negative gate bias exceeded the threshold voltage. The luminescence intensity was increased linearly with increasing the injected current density. The possible luminescence mechanism was briefly discussed and the delta P doping was performed to obtain the doped Si QDs and the improvement of EL intensity was demonstrated.

Abstract: In this paper, a comb-driving tunneling magnetometer based on the tunneling effect is introduced. The designation, manufacture and tests of this magnetometer are discussed, including its structure, FEA analysis, machining processes and test results. The test results indicate that the chip is coincidental with the tunneling effect and the chip is capable of sensing the magnetic signal.

Abstract: Rapid Expansion of Supercritical carbon dioxide Solutions (RESS) containing CO2-soluble, fluorinated ester substituted polythiophene: poly[2-(3-thienyl)acetyl ,3,4,4,5,5,6,6- 7,7,8,8,8,tridecafluoro-1-octanate] (PSFTE) through a small heated micro-orifice (150 .m) produces nanoparticles in the size range of 50 - 300 nm. Pre-expansion temperatures and pressures were found to have marked impact on particle size and morphology. While the particle size increased with more agglomeration with increase in temperature, smaller and spherical particles were produced with increase in pressure owing to the higher solubility of PSFTE in CO2 at high pressures.

Abstract: Our experiments highlight that gold-silicon eutectics are fairly influenced by the thickness of Au layer and the wastage of Si, i.e. the wasting thickness of the silicon die. In the experiments, a bonding intensity testing method, called Press-arm model, is used to verify the Au-Si eutectics bonding strength. Through the intensity value of the bonding interface, we analyze the eutectics condition of the bonding interface at different temperatures and discuss the optimum procession of the wafer capsulation.

Abstract: Polyaniline doped with camphorsulfonic acid (PANI.HCSA) nanofibers have been successfully prepared using “nanofibers template” via electrospinning. The PVA nanofibers were used as a template to get the PANI/PVA composite fibers. After removing the template by heat treatment, the PANI fibers were obtained. Scanning electron microscope (SEM) with the Energy Dispersive X-Ray Spectrometer software (EDX) and FT-IR spectra were used to characterize the composite fibers and the PANI.HCSA nanofibers. The average diameters of the composite fibers obtained and PANI fibers were 920 nm and 530 nm, respectively.

Abstract: The electrospinning technology has been used to fabricate organic nanofibers. As the nanofibers are aligned parallel and crossed, unique electrical and photonic properties are generated. Hereby, a frame of copper thread with a diameter of 0.8 mm was used to collect and align polymer nanofibers. SEM results showed that the nanofibers were parallel aligned between two copper threads. The crossed nanofibers arrays were obtained by layer-by-layer assembling on the parallel nanofibers. The influence factors, such as distance between two copper threads and collection time etc, were investigated.

Abstract: Nano-cell-elements of chalcogenide random access memory (C-RAM) based on Ge2Sb2Te5 films have been successively fabricated by using the focused ion beam method. The minimum contact size between the Ge2Sb2Te5 phase change film and bottom electrode film in the nano-cell-element is in diameter of 90nm. The current-voltage characteristics of the C-RAM cell element are studied using the home-made current-voltage tester in our laboratory. The minimum SET current of about 0.3mA is obtained.