Electronic Devices and Semiconductor Manufacturing Commons^™

Investigations Of Conduction Mechanisms Of Ion-Conducting, Bridging Memory Devices (Cbram/Pmc/Ecm), Kyle Bradley Campbell

Boise State University Theses and Dissertations

Electron storage memory devices are approaching the minimum dimensions that are physically possible due to the onward march of Moore’s law. To continue to enable the increased memory densities needed for today’s applications, especially low power and size constrained mobile devices, new memory solutions are needed. Several candidates are emerging in this space. Metal ion-conducting memory devices are being investigated due to excellent scalability, speed, and low power. These devices are part of a memory class called resistive memory. In the literature, they are referred to as CBRAM (conductive bridge random access memory), PMC (programmable metallization cell), ECM (electrochemical metallization …

Highly Sensitive X-Ray Detectors In The Low-Energy Range On N-Type 4h-Sic Epitaxial Layers, K. C. Mandal, P. G. Muzykov, J. R. Terry

Faculty Publications

No abstract provided.

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 extracted. The extracted specific contact …

Poly(3,4-Ethylenedioxy-Thiophene)：Poly（Styrenesulfonate）（Pedot:Pss） As A Hole-Transporting/Electron-Blocking Interfacial Layer To Increase The Efficiency Of Polymer Bulk-Heterojunction Solar Cells, Yanyu Wu, Michael D. Irwin

COURI Symposium Abstracts, Summer 2012

Solar energy is playing a critical role in today’s renewable energy resources. Polymer bulk-heterojunction solar cells have the possibility to be cost-effective and highly efficient. However, the technology is fairly new and has not yet been perfected. Therefore, In order to enhance the efficiency of polymer bulk-heterojunction solar cells, thin layers of Poly(3,4-ethylenedioxy-thiophene)：poly（styrenesulfonate）（PEDOT:PSS） are inserted between the active organic layer, poly(3-hexylthiophene)(P3HT)+[6,6]-phenyl-C61 butyric acid methyl ester(PCBM), and the ITO(tin-doped indium oxide) anode of bulk-heterojunction ITO/P3HT:PCBM/LiF /Al solar cells. Both the interfacial layer, which is PEDOT: PSS, and the active layer are deposited by spin-coating. So far, I have been able to …

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

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

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 …

Fabrication And Characterization Of Torsional Micro-Hinge Structures, Mike Madrid Marrujo

Master's Theses

ABSTRACT

Fabrication and Characterization of Torsional Micro-Hinge Structures

Mike Marrujo

There are many electronic devices that operate on the micrometer-scale such as Digital Micro-Mirror Devices (DMD). Micro actuators are a common type of DMD that employ a diaphragm supported by torsional hinges, which deform during actuation and are critical for the devices to have high stability and reliability. The stress developed within the hinge during actuation controls how the actuator will respond to the actuating force. Electrostatically driven micro actuators observe to have a fully recoverable non-linear viscoelastic response. The device consists of a micro-hinge which is suspended by two …

Cell Phone Charger For The Dc House Project, Andrew Hefner, Antonio Magdaleno

Electrical Engineering

The goal of this project is to create a multiple output cell phone charger for the DC House project. The cell phone charger is essentially a DC-DC converter. The converter takes an input of 48 volts from the outlet in the DC House and decreases the voltage level to 5 volts; the input voltage level of all cellular devices. By designing an isolated flyback converter with initial specification in LTSpice simulation software, a converter was created. By monitoring the input and output voltage and current using the multi-meters and electronic load, we determined the charger to be 71% efficient when …

Energy Harvesting From Elliptical Machines: Dc-Dc Converter Design Using Sepic Topology, Martin Kou

Master's Theses

Cal Poly’s ongoing Energy Harvesting from Exercise Machines (EHFEM) project is a very convenient and cost-effective way for generating DC power from physical exercise and sending it back to the electrical grid as AC power, providing a renewable energy source for the future. The EHFEM project consists of numerous subprojects involving converting different types of exercise machines for power generation. This project is a continuation of one of the previous subprojects, specifically involving an elliptical machine, and focuses on improving system functionality at different machine settings without altering the elliptical user’s experience by selecting a new DC-DC converter design, while …

Light Extraction Enhancement Of Gan Based Leds Using Top Gratings, Patterned Sapphire Substrates, And Reflective Surfaces, Greg Chavoor

Master's Theses

In the last 15 years, an immense amount of research has gone into developing high efficiency Gallium Nitride based light emitting diodes (LED). These devices have become increasingly popular in LED displays and solid state lighting. Due to the large difference in refractive index between GaN and Air, a significant amount of light reflects at the boundary and does not escape the device. This drawback decreases external quantum efficiency (EQE) by minimizing light extraction. Scientists and engineers continue to develop creative solutions to enhance light extraction. Some solutions include surface roughening, patterned sapphire substrates, and reflective layers.

This study proposes …

Omnidirectional Circularly Polarised Microstrip Patch Antenna, Max Ammann, Adam Narbudowicz, Xiulong Bao

Articles

An omnidirectional circularly-polarised patch antenna is proposed. The antenna radiates right-handed circular-polarisation with an average axial ratio of 2.3 dB over a full 360° . A shallow diagonal CPW inset-feed was used to achieve good matching to the back-to-back coupled patches, providing a measured S11 < -15 dB at the centre frequency. The measured cross-polar performance is better than 13 dB and the realised gain variation is ~3 dB in the plane normal to the substrate.

A Refreshable And Portable E-Braille System For The Blind And Visually Impaired, Mohammad Saadeh, Mohamed Trabia

College of Engineering: Graduate Celebration Programs

• Braille is a communication system to assist the blind and visually impaired.
• Present an approach to measure fingertip forces while identifying Braille characters.
• Implement a force sensory feedback in the device to measure the force developed on the fingertip.
• Introduce a preliminary design for the device.
• Build a prototype for the device and evaluate its functionality and integrate its components

Technology Trends And Predictions: Is A Flying Car In Our Future?, Carol A. Watson

Continuing Legal Education Presentations

Discusses the future of legal research and technologies that are currently available for law offices. Highlights current technology trends and predictions and the latest innovations in courtroom technology. Concludes with a list of general technology predictions that will hopefully provide food for thought and generate excitement about the coming prospects of technology.

Theory Of Charging And Charge Transport In “Intermediate” Thickness Dielectrics And Its Implications For Characterization And Reliability, Sambit Palit, Muhammad A. Alam

Birck and NCN Publications

Thin film dielectrics have broad applications, and the performance degradation due to charge trapping in these thin films is an important and pervasive reliability concern. It has been presumed since the 1960s that current transport in intermediate-thickness (IT) oxides (∼10–100 nm) can be described by Frenkel-Poole (FP) conduction (originally developed for ∼mm-thick films) and algorithms based on the FP theory can be used to extract defect energy levels and charging-limited lifetime. In this paper, we review the published results to show that the presumption of FP-dominated current in IT oxides is incorrect, and therefore, the methods to extract trap-depths to …

Electron Drift-Mobility Measurements In Polycrystalline Cuin1-Xgaxse2 Solar Cells, Steluta A. Dinca, Eric A. Schiff, William N. Shafarman, Brian Egaas, Rommel Noufi, David L. Young

Physics - All Scholarship

We report photocarrier time-of-flight measurements of electron drift mobilities for the p-type CuIn_1-xGa_xSe₂ films incorporated in solar cells. The electron mobilities range from 0.02 to 0.05 cm^2/Vs and are weakly temperature-dependent from 100–300 K. These values are lower than the range of electron Hall mobilities (2-1100 cm²/Vs) reported for n-type polycrystalline thin films and single crystals. We propose that the electron drift mobilities are properties of disorder-induced mobility edges and discuss how this disorder could increase cell efficiencies.

Kreative Outlets, Travis Crist, Steve Clark, Jason Peressini

Computer Engineering

With the widespread use of smart phones and the advancement of WiFi technologies, people now have the Internet at their fingertips at all times. Home automation and control has the possibility of becoming the next big technology that can utilize the abundant availability of the Internet. This paper documents the findings and results of a project aimed at developing the infrastructure needed for a home automation system that is accessible anywhere. We implemented a system that utilized a web enabled ethernet connection and RF wireless technology to control AC outlets and provide the user with feedback information about the status …

Threshold Of Hierarchical Percolating Systems, Jiantong Li, Biswajit Ray, Muhammad Alam, Mikael Ostling

Birck and NCN Publications

Many modern nanostructured materials and doped polymers are morphologically too complex to be interpreted by classical percolation theory. Here, we develop the concept of a hierarchical percolating (percolation-within-percolation) system to describe such complex materials and illustrate how to generalize the conventional percolation to double-level percolation. Based on Monte Carlo simulations, we find that the double-level percolation threshold is close to, but definitely larger than, the product of the local percolation thresholds for the two enclosed single-level systems. The deviation may offer alternative insights into physics concerning infinite clusters and open up new research directions for percolation theory

Can Morphology Tailoring Improve The Open Circuit Voltage Of Organic Solar Cells?, Biswajit Ray, M. S. Lundstrom, Muhammad A. Alam

Birck and NCN Publications

While the effect of interfacial morphology on the short circuit current (I_SC) of organic photovoltaic devices (OPVs) is well known, its impact on open circuit voltage (V_OC) and fill-factor (FF) are less clear. Since the output power of a solar cell Pout = I_SCV_OCFF, such understanding is critical for designing high-performance, morphology-engineered OPVs. In this letter, we provide an explicit analytical proof that any effort to radically improve V_OC by tailoring bulk heterojunction morphology is futile, because any increase in ISC due to larger interface area is counterbalanced by corresponding increase …

A Reconfigurable Cpw Bow-Tie Antenna Using An Integrated Ferroelectric Thin Film Varactor, K. C. Pan, Dustin Brown, Guru Subramanyam, R. Penno, H. Jiang, C. H. Zhang, M. Patterson, David Kuhl, Kevin Leedy, Charles Cerny

Electrical and Computer Engineering Faculty Publications

A novel printed antenna with a frequency reconfigurable feed network is presented. The antenna consists of a bowtie structure patch radiating element in the inner space of an annulus that is on a nongrounded substrate with a ferroelectric (FE) Barium Strontium Titanate (BST) thin film. The bowtie patch is fed by a coplanar waveguide (CPW) transmission line that also includes a CPW-based BST shunt varactor. Reconfiguration of the compact 8 mm × 8 mm system has been demonstrated by shifting the antenna system’s operating frequency 500 MHz in the 7–9 GHz band by applying a DC voltage bias.

Self-Assembly Of Single Dielectric Nanoparticle Layers And Integration In Polymer-Based Solar Cells, Jonathan E. Allen, Biswajit Ray, Mohammad R. Khan, Kevin G. Yager, Muhammad Ashraful Alam, Charles T. Black

Birck and NCN Publications

A single, self-assembled layer of highly uniform dielectric alumina nanoparticles improves the photovoltaic performance of organic semiconductor bulk heterojunction solar cells. The block copolymer based self-assembly approach is readily amenable to the large areas required for solar cell fabrication. A fraction of the performance gain results from incident light scattering which increases active layer absorption and photocurrent output, consistent with device simulations. The nanoparticle layer also roughens the device electrode surface, increasing contact area and improving device fill factor through more efficient charge collection

The Effects Of Deposition Conditions On Rf Sputtered Gallium Tin Zinc Oxide Thin Film Transistors, Tanina Bradley

Dissertations

Thin film transistors (TFTs) were fabricated with a transparent amorphous gallium tin zinc oxide (GSZO) channel layer. GSZO is a promising, low cost replacement for the commonly used indium gallium zinc oxide (IGZO).The transistors were fabricated on Si substrates to optimize performance prior to transferring device production to flexible substrates. This dissertation will address the effects of deposition and post-deposition parameters on the film properties and interface traps. It will also address the parameters’ resultant effects on device performance and stability with the use of various characterization techniques. Film properties were studied using x-ray diffraction (XRD) and transmission measurements to …