Electronic Devices and Semiconductor Manufacturing Commons^™

Organic Solar Cell At Room Temperature, Deedra Zeeh

Thinking Matters Symposium Archive

Organic electronics have become of great interest in the field of materials science research due to the potential for flexible electronic devices and low cost technologies. Difficulties emerge with creating a stable and efficient device, while still maintaining a simple and room-temperature production process.

With the advent of relatively stable organic semiconductors and graphene (or other nanotube or fullerene morphologies), it is possible to fabricate photovoltaic cells at near room temperature. By stacking these cells, devices of reasonable efficiencies >5% can be fabricated. Devices were created with a perylene-P3HT photoactive layer, polyaniline buffer layer, and PEDOT:PSS as the hole transport …

Subtractive Plasma-Assisted-Etch Process For Developing High Performance Nanocrystalline Zinc-Oxide Thin-Film-Transistors, Thomas M. Donigan

Theses and Dissertations

Thin-Film-Transistors (TFTs) employing undoped zinc-oxide (ZnO) thin-films are currently being investigated by the Air Force for microwave switching applications. Since the on-resistance (R(on)) of the device scales with channel length (LC), ZnO TFT optimization should be focused on reducing LC, therefore minimizing the associated insertion losses. In this research, deep sub-micron scaling of ZnO TFTs was undertaken using a subtractive reactive-ion-etch (RIE) process. Under optimum processing conditions, ZnO TFTs with LC as small as 155 nm were successfully demonstrated. The active ZnO channels of the TFTs were patterned by selective SF6-RIE of a tungsten ohmic film through electron-beam defined openings …

Low Clutter Method For Bistatic Rcs Measurements, Peter J. Collins

AFIT Patents

A bistatic radar measurement system is provided having a radar source configured to produce a radio frequency signal. A transmitting antenna is configured to transmit the radio frequency signal toward a target. A receiving antenna is configured to receive a reflected radio frequency signal from the target. A support system is configured to support the receiving antenna. The support system includes a plurality of low scattering dielectric strings configured to orient the receiving antenna.

Electronic Desalting For Controlling The Ionic Environment In Droplet-Based Biosensing Platforms, Vikhram Vilasur Swaminathan, Piyush Dak, Bobby Reddy Jr, Eric Salm, Carlos Duarte-Guevara, Yu Zhong, Andrew Fischer, Yi-Shao Liu, Rashid Bashir

Birck and NCN Publications

The ability to control the ionic environment in saline waters and aqueous electrolytes is useful for desalination as well as electronic biosensing. We demonstrate a method of electronic desalting at micro-scale through on-chip micro electrodes. We show that, while desalting is limited in bulk solutions with unlimited availability of salts, significant desalting of ≥1 mM solutions can be achieved in sub-nanoliter volume droplets with diameters of ∼250 μm. Within these droplets, by using platinum-black microelectrodes and electrochemical surface treatments, we can enhance the electrode surface area to achieve >99% and 41% salt removal in 1 mM and 10 mM salt …

Multiferroic Tunnel Junctions And Ferroelectric Control Of Magnetic State At Interface, Y. W. Yin, M. Raju, W. J. Hu, John D. Burton, Y.-M. Kim, A. Y. Borisevich, S. J. Pennycook, S. M. Yang, T. W. Noh, Alexei Gruverman, X. G. Li, Z. D. Zhang, Evgeny Y. Tsymbal, Qi Li

Alexei Gruverman Publications

As semiconductor devices reach ever smaller dimensions, the challenge of power dissipation and quantum effect place a serious limit on the future device scaling. Recently, a multiferroic tunnel junction (MFTJ) with a ferroelectric barrier sandwiched between two ferromagnetic electrodes has drawn enormous interest due to its potential applications not only in multi-level data storage but also in electric field controlled spintronics and nanoferronics. Here, we present our investigations on four-level resistance states, giant tunneling electroresistance (TER) due to interfacial magnetoelectric coupling, and ferroelectric control of spin polarized tunneling in MFTJs. Coexistence of large tunneling magnetoresistance and TER has been observed …

Investigation Of Gate Dielectric Materials And Dielectric/Silicon Interfaces For Metal Oxide Semiconductor Devices, Lei Han

Theses and Dissertations--Electrical and Computer Engineering

The progress of the silicon-based complementary-metal-oxide-semiconductor (CMOS) technology is mainly contributed to the scaling of the individual component. After decades of development, the scaling trend is approaching to its limitation, and there is urgent needs for the innovations of the materials and structures of the MOS devices, in order to postpone the end of the scaling. Atomic layer deposition (ALD) provides precise control of the deposited thin film at the atomic scale, and has wide application not only in the MOS technology, but also in other nanostructures. In this dissertation, I study rapid thermal processing (RTP) treatment of thermally grown …

Bifacial Si Heterojunction-Perovskite Organic-Inorganic Tandem To Produce Highly Efficient (Η T * ~ 33%) Solar Cell, Reza Asadpour, Raghu Vamsi Krishna Chavali, Mohammad Ryyan Khan, Muhammad Ashraful Alam

Department of Electrical and Computer Engineering Faculty Publications

As single junction photovoltaic (PV) technologies both Si heterojunction (HIT) and perovskite based solar cells promise high efficiencies at low cost. Intuitively a traditional tandem cell design with these cells connected in series is expected to improve the efficiency further. Using a self-consistent numerical modeling of optical and transport characteristics however we find that a traditional series connected tandem design suffers from low JSC due to band-gap mismatch and current matching constraints. Specifically a traditional tandem cell with state-of-the-art HIT ( η=24% ) and perovskite ( η=20% ) sub-cells provides only a modest tandem efficiency of η_T~ 25%. …

Trapping Light With Nanostructures For Sensors, Kareem Garriga

Summer Community of Scholars Posters (RCEU and HCR Combined Programs)

No abstract provided.

Nanostructured Semiconductor Device Design In Solar Cells, Hongmei Dang

Theses and Dissertations--Electrical and Computer Engineering

We demonstrate the use of embedded CdS nanowires in improving spectral transmission loss and the low mechanical and electrical robustness of planar CdS window layer and thus enhancing the quantum efficiency and the reliability of the CdS-CdTe solar cells. CdS nanowire window layer enables light transmission gain at 300nm-550nm. A nearly ideal spectral response of quantum efficiency at a wide spectrum range provides an evidence for improving light transmission in the window layer and enhancing absorption and carrier generation in absorber. Nanowire CdS/CdTe solar cells with Cu/graphite/silver paste as back contacts, on SnO₂/ITO-soda lime glass substrates, yield the …

Strain Controlled Ultra-Low-Energy Magnetic Tunneling Junction, Hasnain Ahmad, Supriyo Bandyopadhyay, Jayasimha Atulasimha

Graduate Research Posters

We are experimenting on designing a voltage-controlled ultra-low-energy Magnetic Tunneling Junction (MTJ) device using a soft single domain magnetostrictive layer (i.e. Galfenol: Fe_1-xGa_x , x = 20 At%) coupled to a piezoelectric layer (i.e. PMN-PT). Special metal pads have been designed using photolithography to generate stress in the PMN-PT layer by applying electric field. The patterns of different shape anisotropic nano-magnets are designed using e-beam lithography and we have successfully fabricate FeGa nanomagnets with only 12 to 13 nanometer thickness by sputter deposition. These nanomagnets have been characterized by magnetic force microscopy for observing their switching capabilities. …

Indirect Matrix Converter As Standard Power Electronic Interface, Andrés Escobar-Mejía

Graduate Theses and Dissertations

The increase in the penetration levels of distributed generation in the modern power grid and its importance in future energy systems have accelerated the interest of developing new power electronic interfaces for the energy conversion process. The feasibility of applying the indirect matrix converter as the standard power electronic interface for applications with power ratings from several kW to few MW is addressed in this dissertation. Special attention is given to those applications where space dominates the power electronic requirements. The main motivation for using the indirect matrix converter is that eliminates the energy storage component in the way of …

Development Of Micro-Hall Devices For Current Sensing, Thomas White

Graduate Theses and Dissertations

In this work, micro-Hall devices were developed for the purpose of sensing current within a high temperature and high power environment. GaAs HEMT, InGaAs pHEMT, and GaN HEMT structures were studied. These structures were grown by molecular beam epitaxy. Processing techniques including photolithography, metallization, Si deposition, wet etching, and dry etching were studied. Electrical characterization measurements including low frequency noise, Hall effect, sensitivity, capacitance-voltage, and current-voltage were performed.

Electron mobility and sheet carrier density studies were performed for both the InGaAs pHEMT and GaAs HEMT structures. Results indicated the InGaAs pHEMT was superior and thus fabricated as the micro-Hall device. …

Buck Converter, Bowen Liu

Electrical Engineering

The recent sustainable energy growth triggered a huge power electronics demand, specifically related to power conversion. My senior project is a design of a buck converter which steps down the voltage from photovoltaic cells ranging from 5 to 40V to a rechargeable battery with 5V. This converter has a high enough power efficiency to effectively convert the energy harnessed from PV panels.

Energy Harvesting From Exercise Machines: Lt8705 Dc-Dc Conversion For Elliptical Trainers, Braden Burk, Raj Bhula, Nathan Mckay

Electrical Engineering

Cal Poly’s Energy Harvesting from Exercise Machines (EHFEM) program aims to power the grid using human energy harvested from exercise machines in its gym. Doing so could save the school money and increase the total supply of power available on the grid. This document belongs to one of many groups attempting to design a suitable DC-DC conversion system for an elliptical trainer using an LT8705 Four-Switch Buck-Boost converter. Past teams have built other converters and developed system compatibility characteristics such as filtering, safety, and stability for interfacing components. These teams fall into one of two departments in EHFEM: DC-DC Conversion …

Gesn Devices For Short-Wave Infrared Optoelectronics, Benjamin Ryan Conley

Graduate Theses and Dissertations

The electronics industry has a large silicon infrastructure for the manufacture of complementary-metal oxide semiconductor (CMOS) based electronics. The increasing density of Si based circuits has set a pace that is now pushing the physical limits of connectivity between devices over conventional wire based links. This has driven the increasing interest in Si based optoelectronics and to use the groundwork already established by the electronics industry for lower cost optical communications. The greatest limitation to this effort has been the incorporation of a Si based laser, which requires integration of a direct bandgap material within this CMOS process.

The Ge1-xSnx …

Design Of A High Performance Silicon Carbide Cmos Operational Amplifier, Shaila Amin Bhuyan

Graduate Theses and Dissertations

This thesis presents the design, simulation, layout and test results of a silicon carbide (SiC) CMOS two-stage operational amplifier (op amp) with NMOS input stage. The circuit has been designed to provide a stable open-loop voltage gain (60 dB), unity-gain bandwidth (around 5 MHz) and maintain a high CMRR and PSRR within a useful input common mode range over process corners and a wide temperature range (25 °C - 300 °C). Between the two stages a Miller compensation topology is placed to improve the phase margin (around 45°). Due to the comparatively high threshold voltage values of transistors in SiC, …

Design, Simulation And Implementation Of Three-Phase Bidirectional Dc-Dc Dual Active Bridge Converter Using Sic Mosfets, Tariq Aldawsari

Graduate Theses and Dissertations

The use of SiC-based martials in fabricating power semiconductor devices has shown more interest than conventional silicon-based. Its promising abilities to improve the performance of power electronic systems made it a valuable choice in building high power DC-DC converters. This thesis presents the design and implementation of a three-phase bidirectional DC-DC Dual Active Bridge using SiC MOSFETs. The proposed circuit is first built in Matlab for simulation analysis. Then a phase shift modulation controller is designed in Simulink to test the simulation circuit. The controls are then integrated through an FPGA to test the prototype. Simulations and experimental results are …

Control Of A Fuel Cell Based Autonomous Electric Power System For An Aerospace Vehicle, Roshini S. Ashok

Von Braun Symposium Student Posters

No abstract provided.

Hybrid Silicon Mode-Locked Laser With Improved Rf Power By Impedance Matching, Bassem M. Tossoun

Master's Theses

The mode-locked laser diode (MLLD) finds a lot of use in applications such as ultra high-speed data processing and sampling, large-capacity optical fiber communications based on optical time-division multiplexing (OTDM) systems. Integrating mode-locked lasers on silicon makes way for highly integrated silicon based photonic communication devices. The mode-locked laser being used in this thesis was built with Hybrid Silicon technology. This technology, developed by UC Santa Barbara in 2006, introduced the idea of wafer bonding a crystalline III- V layer to a Silicon-on-insulator (SOI) substrate, making integrated lasers in silicon chips possible.

Furthermore, all mode-locked lasers produce phase noise, which …

Health Risks Caused By Wireless Technologies, Durreeshahwar Zafarahmed, Qurrat-Ul-Ain Zafarahmed

Journal of Undergraduate Research at Minnesota State University, Mankato

There are many health issues related to the use of cellular phones, wireless local area networks, and other devices that emit electromagnetic radiation (EMR). Some of these systems have become a part of our daily lives and many of us are in direct or indirect contact for extended period of times with these devices. However, the general public is unaware of the health risks associated with the use of these devices. Our research covers studies done by individuals as well as organizations on the harmful effects on the health of people from these devices and their claims. We also present …