Electronic Devices and Semiconductor Manufacturing Commons^™

Cmos Image Sensors With Compressive Sensing Acquisition, Mohammadreza Dadkhah

Open Access Dissertations and Theses

The compressive sensing (CS) paradigm provides an efficient image acquisition technique through simultaneous sensing and compression. Since the imaging philosophy in CS imagers is different from conventional imaging systems, new physical structures are required to design cameras suitable for CS imaging.

While this work is focused on the hardware implementation of CS encoding for CMOS sensors, the image reconstruction problem of CS is also studied. The energy compaction properties of the image in different domains are exploited to modify conventional reconstruction problems. Experimental results show that the modified methods outperform the 1-norm and TV (total variation) reconstruction algorithms by up ...

Investigation Of Cds Nanowires And Planar Films For Enhanced Performance As Window Layers In Cds-Cdte Solar Cell Devices, Jianhao Chen

Theses and Dissertations--Electrical and Computer Engineering

Cadmium sulfide (CdS) and cadmium telluride (CdTe) are two leading semiconductor materials used in the fabrication of thin film solar cells of relatively high power conversion efficiency and low manufacturing cost. In this work, CdS/CdTe solar cells with a varying set of processing parameters and device designs were fabricated and characterized for comparative evaluation. Studies were undertaken to elucidate the effects of (i) each step in fabrication and (ii) parameters like thickness, sheet resistance, light absorptivity solution concentration, inert gas pressure etc. Best results were obtained when the thickness of CdS planar film for the window layer was in ...

A Power Line Inspector Device, Brendan Gates

Honors College

The goal of this project is to create a functional power line inspection device which could replace the old inspection method of using helicopters. This microchip based robotic device is able to ride along a conductor and send video feed, encoder readouts, and temperature measurements to the user. The user operating system consists of an LCD screen, two potentiometers for motor control, and a screen to display video feed. Achieved specifications include a battery lifetime of 1 hour and 45 minutes, distance measurements within 1 inch, and temperature accuracy within 2 °C. This thesis includes a brief discussion on previous ...

Materials Selection And Processing Techniques For Small Spacecraft Solar Cell Arrays, Naseem M. Torabi

Theses and Dissertations--Electrical and Computer Engineering

Body mounted germanium substrate solar cell arrays form the faces of many small satellite designs to provide the primary power source on orbit. High efficiency solar cells are made affordable for university satellite programs as triangular devices trimmed from wafer scale solar cells. The smaller cells allow array designs to pack tightly around antenna mounts and payload instruments, giving the board design flexibility. One objective of this work is to investigate the reliability of solar cells attached to FR-4 printed circuit boards. FR-4 circuit boards have significantly higher thermal expansion coefficients and lower thermal conductivities than germanium. This thermal expansion ...

Anatomical Loading On A Uwb Antenna For Shoe Toe Box, Domenico Gaetano, Patrick Mcevoy, Max Ammann, C Brannigan, Louise Keating, Frances Horgan

Conference Papers

A UWB 6.0-8.5 GHz monopole antenna for mounting on the toe­box area of footwear is designed using a detailed model of a running shoe and a foot-shaped phantom. Variation of anatomical features between individual people gives rise to different proximity and permittivity loads on the antenna. To take account of environment, the antenna design optimization considers different proximity distances for impact on the reflection coefficient and on the radiation efficiency.

A High Performance Modulo 2n+1 Squarer Design Based On Carbon Nanotube Technology, Weifu Li

Electrical and Computer Engineering Master's Theses

Modulo 2ⁿ+1 squarer is widely used in the digital system, such as digital signal processing (DSP), cryptography and residue arithmetic as an important component. In this thesis, an improved high-speed low-power design of modulo 2ⁿ+1 squarer is proposed. The primary improvement comes from algorithm, circuit implementation and implementation technology. For the algorithm, the partial product matrix reconstruction is optimized to achieve a larger range of input and fewer operation steps. Modified Wallace tree is also employed in partial product compression process. For the circuit implementation, full adders in traditional Wallace tree structure are replaced by the ...

Attenuation And Photodetection Of Sub-Bandgap Slow Light In Silicon-On-Insulator Photonic Crystal Waveguides, John L. Gelleta

Open Access Dissertations and Theses

A glass-clad, slow-light photonic-crystal waveguide is proposed as a solution to sub-bandgap light detection in silicon photonic circuits. Such detection in silicon is perceived as a challenge owing to silicon's indirect band gap and transparency to 1550nm wavelengths, yet is essential for achieving low-cost, high-yield integration with today's microelectronics industry. Photonic crystals can be engineered in such a way as to enhance light-matter interaction over a specific bandwidth via the reduction of the group velocity of the propagating wave (i.e. the slowing of light). The interaction enhanced for light detection in the present work is electron-hole pair ...

Mems Resonant Magnetic Field Sensor Based On An Aln/Fegab Bilayer Nano-Plate Resonator, Yu Hui, Tianxiang Nan, Nian Sun, Matteo Rinaldi

Electrical and Computer Engineering Faculty Publications

This paper reports on the first demonstration of an ultra-miniaturized, high frequency (215 MHz) and high sensitivity MEMS resonant magnetic field sensor based on an AlN/FeGaB bilayer nano-plate resonator capable of detecting magnetic field at nano-Tesla level. Despite of the reduced volume and the high operating frequency of the sensor, high electromechanical performances were achieved (quality factor Q ≈ 511 and electromechanical coupling coefficient k_t² ≈ 1.63%). This first prototype was characterized for different magnetic field levels from 0 to 152 Oe showing a frequency sensitivity of ~ 1 Hz/nT and a limit of detection of ~ 10 nT.

Ultra-Fast And High Resolution Nems Thermal Detector Based On A Nano-Air-Gap Piezoelectric Resonant Structure, Yu Hui, Matteo Rinaldi

Electrical and Computer Engineering Faculty Publications

This paper presents the theoretical modeling and experimental verification of an innovative Nano Electro Mechanical System (NEMS) technology suitable for the implementation of ultra-fast and high resolution un-cooled thermal detectors. Fundamental challenges associated to the implementation of mechanically resonant thermal detectors are overcome with the introduction of an innovative technology platform in which a temperature sensitive Aluminum Nitride (AlN) nano-plate resonator and a monolithically integrated micromachined suspended heat absorbing element are perfectly overlapped but separated by a sub-micron air gap. By placing the absorbing element outside the body of the resonator (but suspended over it) the electromechanical performance of the ...

Multi-Mode Self-Referencing Surface Plasmon Resonance Sensors, Jing Guo

Theses and Dissertations--Electrical and Computer Engineering

Surface-plasmon-resonance (SPR) sensors are widely used in biological, chemical, medical, and environmental sensing. This dissertation describes the design and development of dual-mode, self-referencing SPR sensors supporting two surface-plasmon modes (long- and short-range) which can differentiate surface binding interactions from bulk index changes at a single sensing location. Dual-mode SPR sensors have been optimized for surface limit of detection (LOD). In a wavelength interrogated optical setup, both surface plasmons are simultaneously excited at the same location and incident angle but at different wavelengths. To improve the sensor performance, a new approach to dual-mode SPR sensing is presented that offers improved differentiation ...

Experimental Study Of Dkpp-Βt Polymeric Thin Film Transistor, Cong Feng

Open Access Dissertations and Theses

In the last 30 years, the possibility of using polymeric thin film transistors (PTFTs) in flexible display, sensors, radio-frequency identification tag and the potential of using printing or low-cost reel-to-reel fabrication techniques has stimulated much research and technology development in these devices. However, the utilization of PTFTs needs better understanding of the organic semiconductor material’s properties and their physical and chemical mechanisms. In addition, the PTFTs show poor stability compared to the crystalline transistors. The PTFTs can have significant variations of threshold voltage, mobility, on/off ratio even when deposited using the same conditions on the same substrate. Therefore ...

Characterization And Implementation Of An Injection Locked Frequency Divider Based On Relaxation Oscillator, Kai Zhu

Doctoral Dissertations

There has been a dramatic increase in wireless awareness among the user community in the past few years. As the wireless communication devices require more integration in terms of both hardware and software, the low-power integrated circuit (IC) solution has gained higher dedication and will dominate in the future radio-frequency IC (RFIC) design. Complementary Metal-Oxide Semiconductor (CMOS) process is extremely attractive for such applications because of its low cost and the possibility to integrate baseband and high frequency circuits on the same chip. The transceiver is often the most power-hungry block in a wireless communication system. The frequency divider (prescaler ...

Nanostructured Electrodes For Organic Solar Cells: Analysis And Design Fundamentals, Biswajit Ray, Mohammad R. Khan, Charles Black, Muhammad A. Alam

Birck and NCN Publications

Nanostructured electrodes (NEs) improve optical absorption and charge collection in photovoltaic (PV) devices. Traditionally, the electrodes have been designed exclusively for higher optical absorption. Such an optical design of the electrodes does not necessarily ensure better charge collection. Since the efficiency of organic PV (OPV) devices is hindered by the low carrier mobility of the organic semiconductors, the charge collection property of the NEs provides an interesting design alternative. The goal of this paper is the formulation of the essential design rules for NEs to improve charge collection in the low-mobility organic materials. We use detailed optoelectronic device simulation to ...

Is Tech M&A Value-Additive?, Ani Deshmukh

Undergraduate Economic Review

Given rising M&A deal volume across all high-tech subsectors, the ability to measure post-acquisition performance becomes critical. Despite this growth, the relevant academic literature is severely lacking (Kohers and Kohers 2000). Using an event-study approach, I find that acquirers and targets both realize statistically significant day-0 abnormal returns (1.23% [p<0.1] and 8.1% [p<0.01], respectively). As positive stock returns signal positive growth prospects in a semi-strong efficient market, AR regressions found that firms' technological relatedness, deal financing, purchase price premiums, and the relative book to market ratio, explained most variance. Overall, high-tech transactions are value-additive for both targets and acquirers.

Achieving Fill Factor Above 80% In Organic Solar Cells By Charged Interface, Biswajit Ray, Muhammad A. Alam

Birck and NCN Publications

Poor carrier mobility in organic semiconductors and high free carrier recombination at the polymer interfaces hinder efficient collection of photogenerated carriers in organic photovoltaic (OPV) devices. This inefficiency in charge collection is reflected in the low fill factor (FF) of the OPV cells (FFOPV ∼ 65%) compared with its inorganic counterparts (FF ∼ 85%). In this paper, we show that the FF of the OPV devices made of the conventional low-mobility materials can be radically improved (>80%) by introducing a “fixed charge layer” at the donor–acceptor interfaces. We find that the fixed charges prevent free-carrier accumulation at the interface and, hence ...

Role Of Self-Assembled Monolayer Passivation In Electrical Transport Properties And Flicker Noise Of Nanowire Transistors, Seongmin Kim, Patrick D. Carpenter, Rand K. Jean, Haitian Chen, Chongwu Zhou, Sanghyun Ju, David B. Janes

Birck and NCN Publications

Semiconductor nanowires have achieved great attention for integration in next-generation electronics. However, for nanowires with diameters comparable to the Debye length, which would generally be required for one-dimensional operation, surface states degrade the device performance and increase the low-frequency noise. In this study, single In₂O₃ nanowire transistors were fabricated and characterized before and after surface passivation with a self-assembled monolayer of 1-octadecanethiol (ODT). Electrical characterization of the transistors shows that device performance can be enhanced upon ODT-passivation, exhibiting steep subthreshold slope (~ 64 mV/dec), near zero threshold voltage (~ 0.6 V), high mobility (~ 624 cm²/V ...

Nanoscale Contacts Between Semiconducting Nanowires And Metallic Graphenes, Seongmin Kim, David B. Janes, Sung-Yool Choi, Sanghyun Ju

Birck and NCN Publications

Metal–semiconductor (M–S) junctions are important components in many semiconductor devices, and there is growing interest in realizing high quality M–S contacts that are optically transparent. In this paper, we present our investigations into the characteristics of M–S junction in a semiconducting ZnO nanowire that was directly grown on a multilayer graphene film (MGF). The synthesized nanowires were fabricated into two-terminal devices with MGF as one contact and Al as the other contact. By comparison with devices employing Al contacts at both ends, the nanowire resistivity and specific contact resistivity of the MGF–nanowire contact can be ...

Fabrication And Characterization Of Thermomechanically Processed Sulfur And Boron Doped Amorphous Carbon Films, Lonnie Carlson

Chemical & Biomolecular Engineering Theses, Dissertations, & Student Research

Small scale, high power density, reliable, and long-life power supplies would be useful or even critical for space missions or the growing number of microdetectors, microsensors, and miniature vehicles. Alpha or beta particle voltaic devices could satisfy these requirements but have been shown to degrade quickly due to radiation damage. Amorphous carbon (a-C) PN junctions or PIN devices could provide radiation hardness and sufficiently high efficiency. As the range of alpha and beta particles in a-C is ~20-120μm, much thicker films than are typical are needed to maximize collection of the particle energy.

In this work, the fabrication of thermomechanically ...

Lateral Diffusion Lpe Growth Of Single Crystalline Silicon For Photovoltaic Applications, Bo Li

Open Access Dissertations and Theses

A modified liquid phase epitaxy (LPE) technique, called lateral diffusion LPE (LDLPE), is invented for low cost and high efficiency solar cell applications. Potentially, LDLPE is able to produce single crystalline silicon wafers directly from the raw material, rather than cutting wafers from single crystalline silicon ingots, therefore reducing the cost by avoiding the cutting and polishing processes.

By using a traditional LPE method, the silicon is epitaxially grown on the silicon substrate by cooling down the saturated silicon/indium alloy solution from a high temperature. The silicon precipitates on the substrate since its solubility in the indium solvent decreases ...

The Role Of Rare Earth Dopants In Semiconducting Host System For Spin Electronic Devices, Juan A. Colon Santana

Electrical Engineering Theses and Dissertations

The doping of a wide band gap insulator offers an opportunity to increase the coupling between free carriers and magnetic impurities under the magnetic polaron model, leading to an enhanced in the Curie temperature of the host compound, critical for the fabrication of devices with magnetic properties. Some rare earth elements have large intrinsic magnetic moments due to unfilled 4d orbitals, and have been readily incorporated in materials for optical applications. Here the rare earths gadolinium and cerium were explored either as dopants or as part of the high-K semiconducting compound for the fabrication of magnetic heterojunction devices with magnetic ...