Zeitschriftenaufsätze und Buchbeiträge

Layer-structured transition metal dichalcogenides (LS-TMDs) are being heavily studied in K-ion batteries (KIBs) owing to their structural uniqueness and interesting electrochemical mechanisms. Synthetic methods are designed primarily focusing on high capacities. The achieved performance is often the collective results of several contributing factors. It is important to decouple the factors and understand their functions individually. This work presents a study focusing on an individual factor, crystallinity, by taking MoS2 as a demonstrator. The performance of low and high-crystallized MoS2 is compared to show the function of crystallinity is dependent on the electrochemical mechanism. Lower crystallinity can alleviate diffusional limitation in 0.5-3.0 V, where intercalation reaction takes charge in storing K-ions. Higher crystallinity can ensure the structural stability of the MoS2 layers and promote surface charge storage in 0.01-3.0 V, where conversion reaction mainly contributes. The low-crystallized MoS2 exhibits an intercalation capacity (118 mAh g^-1), good cyclability (85% over 100 cycles), and great rate capability (41 mAh g^-1 at 2 A g^-1), and the high-crystallized MoS2 delivers a high capacity of 330 mAh g^-1 at 1 A g^-1 and retains 161 mAh g^-1 at 20 A g^-1, being one of the best among the reported LS-TMDs in KIBs.

High performance single nanometer lithography is an enabling technology for beyond CMOS devices. In this terms a novel mask- and development-less patterning scheme by using electric field, current controlled Scanning Probe Lithography (FE-SPL) in order to pattern structures on different samples was developed. This work aims to manufacture nanostructures into different resist by using FE-SPL, whereas plasma etching at cryogenic temperatures is applied for an efficient pattern transfer into the bottom Si substrate. The challenge for future quantum devices, generated by SPL and cryogenic etching, is finding a resist that is at most 10 nm in thickness and has a plasma durability high enough for pattern transfer into silicon. As a first step towards future quantum devices the silicon-to-resist selectivity of calixarene, AZ Barli, poly (3-hexylthiophen-2, 5-diyl) and polymethylmethacrylat for the anisotropic cryogenic dry etching process was estimated. A silicon-to-resist selectivity of about 4:1 for each of these resists was found. With these results, nano-scale, highly parallel double line features in silicon for future double patterning were generated.

Compliant mechanisms based on flexure hinges are widely used in precision engineering applications. Among those are devices such as precision balances and mass comparators with achievable resolutions and uncertainties in the nano-newton range. The exact knowledge of the mechanical properties of notch hinges and their modeling is essential for the design and the goal-oriented adjustment of these devices. It is shown in this article that many analytical equations available in the literature for calculating the bending stiffness of thin semi-circular flexure hinges cause deviations of up to 12% compared to simulation results based on the three-dimensional finite element model for the considered parameter range. A close examination of the stress state within the loaded hinge reveals possible reasons for this deviation. The article explains this phenomenon in detail and shows the limitations of existing analytical models depending on specific geometric ratios. An accurate determination of the bending stiffness of semi-circular flexure hinges in a wide range of geometric parameters without the need for an elaborate finite element analysis is proposed in form of FEM-based correction factors for analytical equations referring to Euler-Bernoulli's beam theory.