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Flexible radio-frequency (RF) capacitors and inductors on the plastic substrates have been fabricated and characterized under mechanical bending conditions. A novel method to predict the RF performance for them on different bending states is demonstrated. Artificial neural network (ANN) shows good modeling accuracy for the flexible RF passive components with bending strains from dc to resonant frequency ($\sim 13/2$ GHz for the capacitor/inductor). More importantly, the automatically generated ANN model, with no need of repeatedly tuning the model parameters, has demonstrated the ability to predict the RF responses for the flexible capacitors and inductors under arbitrary bending conditions with only a few sets of experimental data. Once established, this model can automatically learn the structure of the input date and predict the actual results on specific bending state which can provide an original method to measure the performance for flexible electronics on even extreme bent radius. The ANN model indicates good potential for accurate design, characterization and optimization of the high-performance flexible electronics.

An approach toward molecular information storage employs redox-active molecules attached to an electroactive surface. The chief advantages of such molecular capacitors include higher charge density and more versatile synthetic design than is afforded by typical semiconductor charge-storage materials. An architecture containing two triple-decker sandwich coordination complexes and an S-acetylthiomethyl-terminated tether has been designed for multibit storage. Each triple decker is composed of two phthalocyanines, one porphyrin, and two europium atoms. The oxidation potentials of each triple decker are tuned through the use of different substituents on the phthalocyanines (t-butyl, methyl, H) and porphyrins (pentyl, p-tolyl). Interleaving of the four cationic oxidation states of each triple decker potentially affords eight distinct oxidation states. Two dyads were examined in solution and in self-assembled monolayers (SAMs) on a Au surface. One dyad exhibited eight distinct states in solution and in the SAM, thus constituting a molecular octal counter. The potentials ranged from −0.1-+1.3 V in solution and +0.1-+1.6 V in the SAM. Taken together, this approach provides a viable means of achieving multibit information storage at relatively low potential.

Porphyrinic molecules have been shown to be viable candidates for a molecular-based information storage medium on the basis of redox activity. An optimal redox-based information storage medium requires a large charge density in the molecular footprint on the anchoring substrate. The use of dimeric versus monomeric architectures affords one route to achieving increased charge density without sacrificing surface cross sectional area. Towards this goal, a series of zinc and cobalt containing porphyrin dimers has been prepared and characterized. The interporphyrin linkages in the dimers include p-phenylene, ethynyl, 1,4-butadiynyl, and ethynylphenylethynyl joining porphyrin meso-positions; Crossley-type fusion bridging porphyrin β-positions, and Osuka-type triple fusions bridging one meso- and two β-positions. The electrochemical features of each dimer have been evaluated.

An approach for information storage employs tetrapyrrole macrocycles as charge-storage elements attached to a (semi)conductor in hybrid chips. Anti-counterfeiting measures must cohere with the tiny amounts of such electroactive material and strict constraints on composition in chips; accordingly, the incorporation of typical anti-counterfeiting taggants or microcarriers is precluded. The provenance of the tetrapyrroles can be established through the use of isotopic substitution integral to the macrocycle. The isotopic substitution can be achieved by rational site-specific incorporation or by combinatorial procedures. The formation of a mixture of such macrocycles with various isotopic composition (isotopically unmodified, isotopologues, isotopomers) provides the molecular equivalent of an indelible printed watermark. Resonance Raman spectroscopic examination can reveal the watermark, but not the underlying molecular and isotopic composition; imaging mass spectrometry can reveal the presence of isotopologues but cannot discriminate among isotopomers. Hence, deciphering the code that encrypts the watermark in an attempt at forgery is expected to be prohibitive. A brief overview is provided of strategies for incorporating isotopes in meso-substituted tetrapyrrole macrocycles.

Ability of epitaxial perovskite oxide ferroelectric films to maintain a poled polarization state on a long-term scale is crucial for advanced devices employing such films. Here polarization relaxation with time, or aging, is experimentally studied in epitaxial capacitor heterostructures of PbTiO₃ sandwiched between SrRuO₃ and Pt electrodes. The relaxation obeys logarithmic time-decay for the time 10²–10⁵s after poling pulses. The decay is by factor $\sim$10 slower than that reported for polycrystalline films. Our experimental results show that existing models are insufficient for epitaxial films.

Ceramics-based capacitors with excellent energy storage characteristics, fast charging/discharge rate, and high efficiency have received significant attention. In this work, ${\text{Na}}_{0.73}$${\text{Bi}}_{0.09}$NbO₃(NBN) ceramics were processed through solid-state sintering route. The investigated ceramics were crystallized in a single perovskite phase. Dense microstructure, with small average grain size ($\sim$0.92 $\mu$m) is obtained for the investigated ceramics. A high dielectric constant $>$1000 accompanied by a low dielectric loss was achieved for these ceramics at ambient temperature. A recoverable energy density $\sim$0.92 J/cm³and ultra-high efficiency of 96.33% at 138 kV/cm were obtained at room temperature. Furthermore, a lower discharging time of 0.14 $\mu$s was also achieved. This material is a suitable candidate for power pulsed applications.

In this work, novel (1 $-x$)(0.75Na${}_{0.5}$Bi${}_{0.5}$TiO₃)-0.25Sr(Zr${}_{0.2}$Sn${}_{0.2}$Hf${}_{0.2}$Ti${}_{0.2}$Nb${}_{0.2}$)O₃-$x$NaNbO₃ (NBT-SZSHTN-$x$NN, $x$ = 0.1, 0.15, 0.2, 0.25) ceramics were fabricated. The influence of co-doping of NN and high entropy perovskite oxide (SZSHTN) on the phase structure, microstructure and dielectric properties of NBT-based lead-free ceramics was investigated. Dense microstructure with a grain size of $\sim$5 $\mu$m is observed. When $x$ = 0.25, a wide dielectric temperature stable range of −35.4–224.3${}^{\circ }$C with a low temperature coefficient of capacitance of $<$ 10% is achieved, fulfilling the industry standard of Y9P specification. Furthermore, excellent energy storage performance with recoverable energy density of 2.4 J/cm³, discharge efficiency of 71%, power density of 25.495 MW/cm³ and discharge rate $<$ 200 ns are simultaneously obtained, which shows great potential for high temperature capacitor applications.

This paper describes a power supply of pulse capacitors. The charging system is designed for charging four 16mF capacitors up to 5kV in approximately 60s. These capacitors then charge the load up to 20kV. This power supply is based on a series resonant inverter followed by a step-up transformer. Simulation results show that the load capacitor voltage increases linearly.

High densities with low voltage coefficients of capacitances (VCCs) of Metal-insulator-metal (MIM) capacitors are required for the application of radio frequency and analog/mixed-signal integrated circuits. In this paper, the MIM capacitors with SiO₂-HfO₂-SiO₂ (SHS) sandwiched dielectrics structures are fabricated. The results indicate that with the proper combination, the SHS dielectrics exhibit high capacitance while remaining relatively low VCCs. For the 1.5 nm individual SiO₂ layers, the MIM capacitor can offer a capacitance density of 9 fF/£m², quadratic voltage coefficients of capacitance of 436 ppm/V², and a leakage current as low as 2.3×10⁻⁸ A/cm² at 1 MV/cm.