NanoTechnology: Materials, Processes & Devices

Research that includes:

  • Development of nanostructure fabrication technology
  • Nanomagnetics, Microphotonics
  • CMOS Integrated Nanowires/Nanotubes (CMOS-Inn)

BPN581: Shape-Controlled Synthesis of Single-Crystalline Nanopillar Arrays by Template-Assisted Vapor-Liquid-Solid Process

Onur Ergen
Daniel J. Ruebusch
Hui Fang
2011

In this work highly regular, single-crystalline nanopillar arrays with tunable shapes and geometry are synthesized by the template-assisted vapor-liquid-solid growth mechanism. The grown nanopillars faithfully reproduce the shape of the pores because during the growth the liquid catalyst seeds fill the space available, thereby conforming to the pore geometry. The process is highly generic for various material systems, and as an example, CdS and Ge nanopillar arrays with square, rectangular, and circular cross- sections are demonstrated. This technique has great potential im many...

BPN577: Ultra-Thin Body, Mixed Anion Arsenide-Antimonide XOI FETs

Hui Fang
Steven Chuang
Kuniharu Takei
Ali Javey
2011

We demonstrate ultrathin body (UTB) high mobility InAsSb-on-insulator (XOI) n-FETs. The devices are obtained by the epitaxial layer transfer (ELT) of ultrathin InAsSb layers (thickness, 7-17 nm) onto Si/SiO2 substrates. InAsSb XOI FETs exhibit a peak effective mobility of ~5000 cm2/V-s and an ION/IOFF ratio of over 104. The top-gated devices exhibit an impressive ION of ~0.24 mA/μm (LG~500 nm) at VDD=0.5 V and a SS of ~109 mV/dec. These results demonstrate the utility of the XOI platform for obtaining high mobility n-FETs on Si by using mixed anion arsenide-antimonide as the active...

BPN504: Magnetic Particle Imaging of Superparmagnetic Iron Oxide Nanoparticles

Patrick Goodwill
Laura Croft
Justin Konkle
Kuan Lu
Arbi Tamrazian
Bo Zheng
2011

We have developed a new, ultra-sensitive and affordable 3D scanner designed to image the distribution of a magnetic nanostructure contrast agents in vivo. MPI has several important advantages over existing imaging methods, such as MRI, ultrasound, nuclear medicine, and CT. First, the Magnetic Particle Imaging scanner directly detects a nanoparticle's electronic magnetism, which is 1 million times more intense than the nuclear paramagnetism detected in MRI, so this new modality promises unprecedented contrast-to-noise ratio (CNR). MPI employs MRI nanoparticle contrast agents, which...

BPN507: Ultra-low Voltage Field Ionization of Gases in Vacuum and Atmospheric Pressure Based on Semiconductor Nanotips

Jackie Jinyong Oh
Avinash Nayak
2011

This project aims to develop highly sensitive, real-time and low voltage gas ionization sensors. We have successfully fabricated and characterized branched silicon nanowhiskers with extremely sharp tips. Arrays of these sharp tips are used because of their small tip radii and high aspect ratio which allow for high electric fields at low voltages. When the device is biased, the nanowires are at the highest potential and the collector (anode) is at the lowest potential, at this stage the electrons in the outer shell of the gas atoms (molecules) tunnel out due to the large geometrical...

BPN579: Top-Down and Bottom-Up Approaches to Anti-Reflective Templates for Efficient Photoelectrochemical Solar-to-Fuel Conversion

Cary Pint
2011

Due to tightened regulations on environmental control and high demand on clean fuel, there is great interest in developing a method whose process and product are both eco-friendly. Hydrogen is a fuel of high quality and zero emission. Hydrogen can be directly produced by splitting water into H2 and O2. This project focuses on photochemical splitting of water using solar energy and InP as the photocatalyst. In an effort to enhance the efficiency, the InP is textured to have very low reflectivity.

Project end date: 08/19/11

BPN465: Conformal Ultra-shallow Junction Formation for 3-D Structured InP Nanopillar Solar Cell

Kee Cho
Onur Ergen
Rehan Kapadia
2011

Solar energy represents one of the most abundant and yet least harvested source of renewable energy. We report a PV structure that incorporates 3D, single crystalline n-CdS nanopillars, embedded in poly- crystalline thin films of p-CdTe, to enable high absorption of light and efficient collection of the carriers. Through experiments and modeling, we demonstrate the potency of this approach for enabling highly versatile solar modules on both rigid and flexible substrates with enhanced carrier collection efficiency arising from the geometric configuration of the NPLs. We performed...

BPN549: Laser-Based Synthesis of Nanostructures

Richard Winslow
2011

Current methods of growing nanostructures use bulk fabrication processes. Examining new methods to focus where and how these structures are synthesized will allow more complex devices to be made. Lasers can act as an energy source that locally heats material. By concentrating lasers on specific thin films during processing, nanostructures can be grown over small areas with greater precision. This process will also provide a means to grow very different structures within close proximity to each other. Finally, the amount of heat transferred to the films can be fine-tuned with the...

BPN513: Direct Synthesis of High Density Mono-Dispersed Gold Nano Particle and Biomedical Applications

Young Geun Park
2011

Many preparation methods for gold nano particle in ordered frame work or substrate have been invented to achieve high optical sensitivity and selectivity, however the complicate and long each step has leaded to low productivity and cost problem for commercialization. In this study, we report a direct synthesis of gold nano particle via meso porous silica thin film with long range orderness. In mesoporous silica thinf film, we introduced self assembly method via using tri- block copolymer. Especially, the hydrophilic part of tri-block polymer shows hydrophilic characteristics, and...

BPN647: Ultra-Thin Body, Mixed Anion Arsenide-Antimonide XOI FETs

Hui Fang
Steven Chuang
Kuniharu Takei
2011

We demonstrate ultrathin body (UTB) high mobility InAsSb-on-insulator (XOI) n-FETs. The devices are obtained by the epitaxial layer transfer (ELT) of ultrathin InAsSb layers (thickness, 7-17 nm) onto Si/SiO2 substrates. InAsSb XOI FETs exhibit a peak effective mobility of ~5000 cm2/V-s and an ION/IOFF ratio of over 104. The top-gated devices exhibit an impressive ION of ~0.24 mA/micron (LG~500 nm) at VDD=0.5 V and a SS of ~109 mV/dec. These results demonstrate the utility of the XOI platform for obtaining high mobility n-FETs on Si by using mixed anion arsenide-antimonide as the...

BPN474: Micro CVD for Nanostructure Synthesis

Qin Zhou
2011

This project intends to miniaturize the conventional chemical vapor deposition (CVD) system into the micrometers range in dimension. It is believed that Micro-CVD provides better control on the gas flow, gas temperature and gas species in some aspects. This may result in the sythesis of unique nanostructures with new properties. Based on the idea, a prototype micro machined silicon structure is fabricated in the Microlab and is used to synthesize carbon nanotubes (CNTs) and graphene. The CNTs can directly be grown on varies of substrate including paper and plastic, and they are of...