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Cu-Zn alloy micropillars were fabricated by a potentiostatic localized electrochemical deposition (LECD) process. This process was carried out via micro-anode-guided electroplating in a pyrophosphate bath at a constant negative potential in the range −1.85 to −2.05 V. Different products were produced, depending on the initial inter-electrode gap employed. Thus, at an initial gap of 40 μm, the process afforded micropillars with a single α-brass crystal phase and at.% Zn contents in the range 17.20–32.01%. A reduction in the initial gap to 30 μm resulted in varied micropillar crystal phases (α, β, and β + β') with at.% Zn contents in the range 37.12–68.94. The simulation commercial software COMSOL 5.2 was employed to correlate the asymmetric distribution of the electric field to the experimental parameters and pillar characteristics. The resultant data was then used to delineate the dependence of the field strength on the crystal phase, composition, growth rate, and micropillar diameters. Finally, a potentiodynamic cathodic polarization study was employed to elucidate the mechanism for the fabrication of the Cu-Zn alloy micropillars via potentiostatic LECD.

Lithium metal anode has been regarded as the "Holy Grail" of next-generation battery technologies. In order to stabilize the electrodeposited Li metal for safe and high energy batteries, highly concentrated electrolytes (solvate electrolytes) have been proposed to suppress the formation of Li dendritic structure and polysulfide dissolution in lithium-sulfur (Li-S) batteries. (1-5) In this talk, we use in situ transmission X-ray microscopy (TXM) to study the effect of solvate electrolyte on Li plating/stripping process. In situ TXM images show that electrodeposited Li particles with uniform density are formed in solvate electrolyte during initial plating process. The effect of solvate electrolyte on the mechanism of Li growth is studied in detail. Additionally, in situ spectroscopy including Raman and X-ray spectroscopy (X-ray diffraction and X-ray absorption spectroscopy) are used to investigate sulfur reaction mechanism and the interaction between polysulfide and solvate electrolyte. We found that the sulfur species formed in the solvate electrolyte are different from the sulfur species formed in conventional DOL/DME electrolyte. These results suggest that solvate electrolyte changes both polysulfide solubility and sulfur reaction mechanism. We next propose different solvate electrolytes with low polysulfide solubility and high stability toward Li metal to enhance the capacity retention of Li-S batteries. References: [1] L. Suo et al., Nat. Commun. 2013, 4, 1481. [2] K. Dokko et al., J. Electrochem. Soc. 2013, 160, A1304. [3] M. Cuisinier et al., Energy Environ. Sci., 2014, 7, 2697. [4] Y. Yamada et al., J. Electrochem. Soc. 2015, 162 (14), A2406. [5] L. Cheng et al., ACS Energy Lett. 2016, 1, 503.

Si nanocrystal with a high density of 5.1 X 10 11 cm -2 and an average size of 7.2 nm has been achieved on the NH 3 -nitrided tunnel oxide, and the density is higher than that formed on the untreated tunnel oxide by a factor of 3.2. The higher density obtained by this technique is attributed to the lower activation energy for the Si nanocrystal nucleation growth on the nitrogen-containing surface of the nitrided tunnel oxide. The memory device with such a high nanocrystal density demonstrates a 1.79 V threshold voltage shift by programming at 10 V for 10 ms and a negligible memory window degradation up to 10 6 program/erase cycles. The good charge storage capability is evidenced by an extrapolated 10 year memory window of 0.92 V at 150°C.

A newly developed storage dielectric was found to have exceptional competence to prolong the life span of existent NO-based dielectrics by adopting N 2 O wet oxidation and postoxidation treatment. Compared with the conventional NO dielectric, 12.6% cell capacitance enhancement can be achieved while keeping a comparable leakage current. The reliability performance is also qualified with less than 438 ppm failure rate after 10-years of operation. In addition to the distinguished electrical characteristics, the intriguing point is its process simplicity since the N 2 O-related process could be fully integrated into the current furnace process. Combining the promising properties, this economical technique would be favorable for dynamic random access memory (DRAM) manufacturers to control their chip cost in the increasingly competitive arena.