NanoTechnology: Materials, Processes & Devices

Research that includes:

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

BPN517: Facile Synthesis of Nanostructures for Renewable Energy and Gas Sensing Applications

Kevin Limkrailassiri
2013

Oxide semiconductors have been attracting great interest for renewable energy and sensing applications due to their earth- abundance, stability, and cost-effectiveness. In this project, we explore cupric oxide (CuO) nanowires, which are grown in highly dense and vertically aligned arrays via thermal oxidation of copper foil in ambient air. This material shows great promise for photoelectrochemical hydrogen evolution owing to a desirable electronic band gap and exceptional light-trapping properties. Initial results reveal a photocurrent comparable to other high-performing oxide...

BPN625: Direct Growth of High Quality III-V Semiconductors on Metal Foils for Low-Cost, High-Efficiency PVs

Maxwell S. Zheng
Zhibin Yu
Rehan Kapadia
2013

The intrinsic advantages of III-V semiconductors for solar cells have been hobbled by the lack of low-cost substrates and processes, which has thus far limited market success of III-V solar cells. Here at Berkeley we are exploring a non-traditional approach which addresses these drawbacks. High optical quality polycrystalline InP films have been grown on non-epitaxial molybdenum substrates. Remarkably, these films with micron-sized grains have similar photoluminescence qualities as single- crystalline InP, and show great promise for high-efficiency, low-cost solar cells....

BPN750: Multi-Gas Detecting Chemical Sensor Platform

Hiroshi Shiraki
2014

Chemical sensitive field effect transistors (CS-FET), which are conventional MOSFETs without gate electrodes will be fabricated and applied for low energy consumption, highly sensitive, small size, multi-gas detecting chemical sensors. The work functions of transition metal oxides (TMOs) deposited onto the channels of the CS-FETs can be manipulated by the adsorption of chemicals onto their surfaces. These changes cause a change in the surface potential of the underlying Si channel, leading to the current modulation of the devices. By selecting appropriate TMOs, different chemicals...

BPN752: Highly Efficient and Stable Photocathode for Solar Hydrogen Production

Yongjing Lin
Corsin Battaglia
Joel W. Ager
2014

Solar hydrogen production by photoelectrochemical water splitting holds great promise for efficient solar energy harvesting and storage. To achieve spontaneous water splitting, developing efficient photoelectrodes with both high photovoltage and high photocurrent is highly desirable. However, current studied photocathodes such as p-Si, p-Cu2O and p-GaP have photovoltage lower than half of 1.23 V, the minimum voltage required for water splitting. To overcome these challenges, we are currently developing a photocathode using amorphous Si thin film with TiO2 encapsulation layer for...

BPN748: Highly Sensitive Electronic Whiskers Based on Patterned Carbon Nanotube and Silver Nanoparticle Composite Films

Zhibin Yu
2014

Mammalian whiskers present an important class of tactile sensors that complement the functionalities of skin for detecting wind with high sensitivity and navigation around local obstacles. Here, we developed electronic whiskers based on highly tunable composite films of carbon nanotubes and silver nanoparticles that are patterned on high-aspect ratio elastic fibers. The nanotubes form a conductive network matrix with excellent bendability, while nanoparticle loading enhances the conductivity and endows the composite with high strain sensitivity. The resistivity of the composites is...

BPN606: Carbon Nanotube Films for Energy Storage Applications

Alina Kozinda
Caiwei Shen
2014

As energy demands continue to rise, it becomes imperative to develop efficient energy storage devices with high energy and power density. At the same time, the space inside devices continues to shrink, making energy storage devices which possess not only high energy/power density, but also an adjustable shape to fit into various form factors an ideal solution. Energy storage devices made from flexible electrodes are attractive in a roll-up or surface-conformed format to minimize space usage. A mechanically flexible CNT supercapacitor electrode is demonstrated, as well as a lithium-...

BPN518: Synthetic Turing Patterns

Justin Hsia
2015

Understanding symmetry breaking is at the heart of developmental biology, from the origins of polarity, cellular differentiations, and how the leopard got its spots, as well as crucial to the future engineering of complex cellular ensembles. Alan Turing proposed a simple mathematical model that explains how the reaction-diffusion mechanism can cause an initially uniform concentration in an ensemble of cells to spontaneously become non-uniform and form patterns (Turing patterns). To date, no true synthetic Turing patterns have been created using gene networks, so our goal is to design...

BPN727: On-Chip Single Molecule miRNA Detection for Cancer Diagnosis

Julian A. Diaz
Sang Hun Lee
2015

Early stage cancer diagnosis may mean the difference between a successful or an ineffective treatment. Therefore, development of methods that allow the detection of premature signatures of cancer are necessary. Mature microRNAs are short non-coding RNAs strands (~18-21 nt) involved in gene regulation of eukaryotic cells. In cancer cells some miRNAs appear over or under expressed, and serve as a markers to signal the presence of these malignancies. MicroRNAs, however, are present in very low concentrations, thus sensitive and multiplexed methods that detect specific miRNAs are needed...

BPN792: Thin Film InP Photoelectrochemical Cells for Efficient, Low-Cost Solar Fuel Production

Mark Hettick
Maxwell Zheng
2015

While bulk p-type InP wafers have produced high efficiency photoelectrochemical water- splitting cells, the high cost of epitaxial substrates limits viability at a larger scale. Here, we utilize low-cost growth of InP on non-epitaxial substrates with the thin-film vapor- liquid-solid method to provide high efficiency, scalable photocathode cells for the hydrogen evolution reaction.

Project end date: 08/19/15

BPN776: Wearable Electronic Tape

Hiroki Ota
Kevin Chen
2015

We demonstrate a high-performance wearable piezoelectric electronic-tape (E-tape) for motion sensing based on a carbon nanotube (CNT)/silver nanoparticle (AgNP) composite encased in PDMS and VHB flexible thin films. E-tape sensors directly attached to human skin exhibit fast and accurate electric response to bending and stretching movements which induce change in conductivity with high sensitivity. Furthermore, E-tape sensors for a wide range of applications can be realized by the combination of controlling the concentration of AgNPs in the CNT network and designing appropriate...