This work presents a novel miniaturized Rosen transformer fabricated on a 128 degrees Y-cut lithium niobate wafer. In this design, optimized tethers and acoustic reflectors are carved out of the substrate, enabling a compact implementation of the Rosen transformer with superior quality factor and voltage gain. Measured results from the first-generation device exhibit a quality factor (Q) of approximately 4,700 in air with a measured voltage gain of similar to 50. Simulations based on the extracted electrical model indicate a peak efficiency of 70% for a 126 k Omega load, an open-circuit voltage gain of 84, and a figure of merit of similar to 130.

This work presents a novel third order flexural-mode lithium niobate on silicon MEMS piezoelectric transformer (PT), designed for passive voltage gain and impedance transformation without the need for magnetic components. The PT was designed using COMSOL Multiphysics simulations and fabricated using a 2 mu m lithium niobate film bonded to a platinum-coated silicon on insulator (SOI) wafer. The device operates in an out-of-plane flexural mode enabled by a silicon elastic layer, achieves an equivalent transformation ratio of 1:2.1, an open circuit voltage gain of 4.85, and a peak efficiency of 58%. Vector network analyzer (VNA) measurements yielded a quality factor (Q) and effective electromechanical coupling factor (k(eff)(2)) of similar to 335 and similar to 2.2%, respectively.

In this research, the work function (WF) of RF sputtered GZO thin films has been estimated using the electrical characteristics n-Metal Oxide Semiconductor Field Effect Transistor (n-MOSFET) device. Two identical sets of MOSFETs were fabricated in this work using a four-level mask. These MOSFETs have two different types of gate contact materials (Al and GZO respectively). GZO was deposited by using RF magnetron sputtering technique while Al was deposited using the thermal evaporation technique. By comparison of the work function of the two MOSFETs, the work function of RF sputtered GZO thin films was identified to be around 4.58 eV.

For the first time in the literature, the material properties of gallium-doped zinc oxide, grown from a high impulse magnetron sputtering system (HiPIMS), are reported. These material properties are compared to those of a typical radio frequency (RF) sputtering deposition. The films were grown without thermal assistance and were compared across multiple average deposition powers. The films’ resistivity, crystallinity, absorption coefficient, band gap, and refractive index were measured for each of the samples. It was observed that very similar results could be obtained between the HiPIMS and RF sputtering processes under the same average power conditions. It was found that the RF depositions demonstrated a slightly higher band gap and deposition rate as well as lower resistivity and optical absorption coefficient. Band gaps and grain size were found to increase with the power of the deposition for both HiPIMS and RF. These values ranged between 3.45 eV and 3.79 eV and 9 nm and 23 nm in this study, respectively. The absorption coefficient and resistivity were both found to decline with increasing power in both methods but reached minimums of 2800 cm−1 and 0.94 mOhm-cm, respectively, when sputtered using an RF power supply.

This work reports on the electrodeposition of zinc on nanoporous metal oxide titania nanotube arrays (TiO2 NTAs) using a zinc-containing deep eutectic solvent (Zn2+-DES). The effects of substrate morphology and crystallinity, deposition temperature, zinc concentration, and deposition time on the morphology and electrochemical properties of the Zn/TiO2 NTAs were investigated. Two-dimensional zinc nanohexagons (NHexs) with a mean diameter of similar to 300 nm and a thickness of 10-20 nm were decorated onto the TiO2 NTAs (with a pore diameter of similar to 80 nm and a tube length of similar to 5 mu m) via electrodeposition at -1.6 V using Zn2+-DES. Cyclic voltammetry tests on the Zn2+-DES electrolyte revealed an electrochemical window of similar to 3.5 V, and the diffusion coefficient of Zn2+ was found to be 4.29 x 10-10 cm2 s-1 at room temperature and 7.10 x 10-10 cm2 s-1 at 40 degrees C. Zinc nucleation on TiO2 NTA substrates followed an instantaneous model. Using a higher electrodeposition temperature increased the nucleation and growth rate of zinc NHexs, while annealing TiO2 NTAs was found to improve their uniformity and morphology. During the initial stage of deposition, hexagonal close-packed zinc NHexs were found to preferentially grow on tetragonal anatase TiO2 NTAs. The electrodeposition of zinc resulted in lowering the impedance and improving the overall electrochemical properties of TiO2 NTAs. The Zn/TiO2 NTAs developed in this study offer a promising electrocatalyst material system for implantable electrochemical sensors.

We describe a controllable infrared plasmonic laser attenuator with application to infrared detector characterization. The device promises a broad range of effective radiant temperature and fine temperature control/resolution near ambient. The enabling mechanism is controllably-frustrated surface-plasmon-resonance using a Kretschmann prism coupler. The predicted wide dynamic range depends on optical and geometric tolerances for the coupler. To investigate these, a mid-wave-infrared coupler comprising a conducting Ga-doped ZnO film deposited directly on a right-angle sapphire prism was fabricated, tested, and compared with theory. The attenuation resonance was observed by measuring specular reflection of a p-polarized quantum cascade laser beam at 4.45 mu m wavelength as a function of internal incidence angle from the coated prism face. The predicted resonance for comparison was based on ellipsometrically-obtained optical constants and film thickness. Near perfect match between theory and experiment was achieved after adjusting for experimental uncertainties in optical parameters. The results quantify the accuracy and precision with which optical constants and geometrical parameters must be known to achieve the predicted performance.

We describe a variable attenuator for use with conventional IR quantum cascade or carbon dioxide lasers to create a source with widely and rapidly controllable effective radiant temperature. This would have application to testing of imagers, which must observe scenes that change rapidly between ambient background and very hot objects. The mechanism is controllably frustrated surface plasmon resonance. The device comprises an IR transparent prism with one face coated by a semitransparent (optically-thin) semiconductor having suitable infrared plasma frequency, followed by a controllable gap to a conventional metal mirror. For the mid-wave infrared band (MWIR, 3-5 micron wavelength), we consider a sapphire hemicylindrical prism coated with the transparent conductor gallium-doped ZnO (GZO). For the long-wave infrared band (LWIR, 8-12 micron wavelength), we consider an undoped-Si prism with one heavily-doped surface. Due to the exponential decay of the surface-plasmon-polariton evanescent wave above the conducting film, the log of internal reflectance of the conducting film decreases linearly with increasing gap, typically by about 1 decade per micron, with a total variation of over 5 orders of magnitude. The effective radiance is determined by laser intensity, reflectance, and reflected-beam divergence. Comparison of the effective radiance values to the band radiance of a black body indicates effective radiant temperatures that can be varied from 300 to over 4000 K for a mirror diameter of 100 (MWIR) or 650 (LWIR) microns. At low effective radiant temperature the device can provide 0.1 K resolution.

This work presents a novel out-of-plane actuator that is composed of a single thin-film piezoelectric layer. The devices are implemented based on a platinum-coated silicon substrate to which a lithium niobate (LN) film is bonded. The out-of-plane movement of the single-layer piezoelectric film is enabled by the unique piezoelectric properties of LN, while a relatively large movement is achieved due to the large coupling coefficients of the film combined with the optimized alignment of the actuation arms to proper LN crystalline orientation. The process flow designed for the fabrication of these devices is detailed, and the preliminary test results are presented. In situ SEM imaging was conducted to quantify the amount of displacement, which is observed to be 4µm for an applied voltage of ±25V in a 250x250 µm2 device.

Long wave infrared imaging systems require small, low cost and low power systems operating at room-temperature. Seebeck nanoantennas are room temperature detectors which generate voltage due to incident electromagnetic radiation, they also provide polarization sensitivity, directivity, small footprint, tunability and the possibility of integration into electronic and photonic circuits. In this work different materials and fabrication processes used in Seebeck bowtie nanoantennas are numerically simulated in order to optimize its response in the long wave infrared region of the electromagnetic spectrum (8–14 μm.) Gold bowtie nanoantennas with thermoelectric connections made of Bi3Te2 and Sb3Te2 showed the highest responsivity values of 9 V/W for gold bowtie nanoantennas on a SiO2 substrate and 240 V/W for gold bowtie free-standing structures. Computer simulations also showed that the thermoelectric response of these detectors add linearly when connecting them in series.

The power grid is facing an unprecedented increase in penetration from solar energy resources. Solar panels are often installed together with battery storage systems to reduce the variability and uncertainty of the intermittent solar energy. In this paper, a methodology for finding the optimal ratio of storage for a given number of solar panels is presented. The methodology is based on an iterative approach that uses real weather data and load data to simulate the different system configurations. The configurations were found as a function of the desired level of system autonomy from the grid which would run for a user-defined amount of time without falling out of specifications due to component aging. Identifying the optimal ratio of storage per panel for a given autonomy requirement has a large impact on both the cost and the performance of the system.

This paper presents a Smart Battery Management System (SBMS) for integrated PV, Microinverter with Lithiumion battery pack. The battery in the integrated module is mainly dedicated to store the excess power generated from the PV panel. The battery also operates as a backup power source to compensate for the power mismatch between the source and the load. Therefore, the incorporated management system in the integrated module is necessary for balancing, protecting, and optimizing the lifetime of the battery. The proposed SBMS aims to optimize the battery capacity of each PV panel, provides thermal management strategy, and Master Controller Unit (MCU). MCU is the main controller which includes control algorithm for the 3-port microinverter and estimates the state-of-functions such as state-of-charge (SOC) and state-of-health (SOH) to make the integrated system more secure, reliable, and cost effective. In the paper, the optimum battery size has been simulated, the algorithm for MCU is described with battery model, and the battery modelling and state-of-functions have been theoretically and experimentally verified.

A variable attenuator for high-powered IR beams, based on MEMS-controlled excitation of surface plasmon polaritons on suitably conducting surfaces is described. Materials choice determines the useful spectral band. Intensity variation over nine-orders is theoretically possible.