NanoTechnology: Materials, Processes & Devices

Research that includes:

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

BPN834: Direct Formation of Pore-Controllable Mesoporous SnO2 for Gas Sensing Applications

Won Seok Chi
Hu Long

Amphiphilic graft copolymer self-assembly provides an effective method to create mesoporous structures that can act as templates for the synthesis of inorganic materials with controlled morphology. In this project, we are using PVC-g-POEM graft copolymer as a template for mesoporous SnO2 fabrication directly onto a microheater platform for gas sensing applications. The sol-gel solutions are composed of PVC-g-POEM and SnO2 precursor with tunable composition allowing the formation of various structures with controllable pore size, and surface area. The mesoporous SnO2 structure is...

BPN813: Novel Hierarchical Metal Oxide Nanostructures for Conductometric Gas Sensing

Ameya Rao

Semiconducting metal oxides have been extensively studied as sensing materials for conductometric gas sensors. Nanostructured metal oxides integrated with miniaturized heating elements have been shown to exhibit particularly high sensitivity while maintaining low power consumption. However, the incorporation of nanostructured metal oxide films onto miniaturized heater-based sensing platforms commonly suffers from uncontrollability in film thickness and microstructure, which reduces sensor performance and fabrication reproducibility. We have developed a controllable and flexible...

BPN777: Nonepitaxial Growth of Single Crystalline III-V Semiconductors onto Insulating Substrates

Kevin Chen
Sujay Desai

III-V semiconducting materials have many characteristics such as high electron mobilities and direct band. gaps that make them desirable for many electronic applications including high performance transistors and solar cells. However, these materials generally have a high cost of production which significantly limits their use in many commercial applications. We aim to explore new growth methods which can grow high quality crystalline III-V films, using InP as an example substrate, onto non-epitaxial substrates. In addition to excellent crystal quality, critical considerations...

BPN800: Solution Processed Oxide Materials

Hyun Sung Park

Recently there has been growing interest in transparent conductive oxides(TCOs) and oxide semiconductors, they are key components for future transparent electronics devices. But there are needs for finding new TCOs and oxide semiconductors because the Indium and Galium are expensive rare earth material and the price is still increasing. Also, conventional vacuum based process is a problem for large scale and complicated geometry devices. In this project, I introduced new TCO material(ATO) and oxide semiconductor for the future transparent electronics devices by using solution process...

BPN881: Strain-Engineered Growth of Two-Dimensional Materials

Geun Ho Ahn
Matin Amani

The application of strain to semiconductors allows for controlled modification of their band-structure. This principle is employed for the manufacturing of devices ranging from high- performance transistors to solid- state lasers. Traditionally, strain is typically achieved via growth on lattice-mismatched substrates. For two- dimensional (2D) semiconductors, this is not feasible as they typically do not interact epitaxially with the substrate. Here, we demonstrate controlled strain engineering of 2D semiconductors during synthesis by utilizing the thermal coefficient of expansion (...

BPN672: Solar Hydrogen Production by Photocatalytic Water Splitting

Emmeline Kao
Neil Ramirez

Hydrogen is a promising, environmentally-friendly fuel source for replacing fossil fuels in transportation and stationary power applications. Currently, most hydrogen is produced from non-renewable sources including natural gas, oil, and coal. Photoelectrochemical (PEC) water splitting is a new renewable energy technology that aims to generate hydrogen from water using solar energy. When light is absorbed by the photocatalyst, an electron-hole pair is generated that interacts with water molecules in a surface reduction-oxidation reaction to decompose the water into hydrogen and...

BPN887: Edge Recombination Velocity of 2D Materials

Peida Zhao
Matin Amani

Deep study of various 2D transition metal dichalcogenide material edge defects and their respective edge recombination velocity. Also includes investigation into possible passivation schemes to further reduce the ERV of respective 2D materials.

Project end date: 08/07/18

BPN895: Infrared Photodetectors Based on 2D Materials

Matin Amani
James Bullock
Chaoliang Tan

Two-dimensional (2D) materials, particularly black phosphorus (bP), have demonstrated themselves to be excellent candidates for high-performance infrared photodetectors and transistors. However, high-quality bP can be obtained only via mechanical exfoliation from high-temperature- and high-pressure-grown bulk crystals and degrades rapidly when exposed to ambient conditions. Here, we report solution-synthesized and air-stable quasi-2D tellurium (Te) nanoflakes for short-wave infrared (SWIR) photodetectors. We perform comprehensive optical characterization via polarization-resolved...

BPN862: 2D Semiconductor Transistors with 1-Nanometer Gate Length

Sujay B. Desai
Chunsong Zhao

MoS2 transistors with a 1-nm physical gate length using a single-walled carbon nanotube as the gate electrode are demonstrated. These devices exhibit near ideal subthreshold swing ~65 millivolts per decade and an On/Off current ratio ~10^6. This work provides new insight into the ultimate scaling of gate lengths for a FET by surpassing the 5 nm limit often associated with Si technology. Furthermore, the impact of using gate electrodes with limited density of states on the characteristics of nanoscale transistors is studied. Current work involves self- aligned doping of the extension...

BPN822: Monolayer Semiconductor Optoelectronics

Hyungjin Kim
Matin Amani
Der-Hsien Lien

In spite of the great promise they hold for a broad range of applications, two- dimensional (2D) transition metal dichalcogenides (TMDCs) have had a significant drawback of poor photoluminescence (PL) quantum yield (QY) at room temperature. Among a number of studies which have suggested the way to improve QY, superacid treatment, one of the most promising strategies, has enhanced the QY of TMDCs to near 100%. However, insufficient treatment yield and instability of enhanced QY have emerged as critical obstacles to this approach towards practical applications in real devices. In this...