NanoTechnology: Materials, Processes & Devices

Research that includes:

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

BPN881: Strain-Engineered Growth of Two-Dimensional Materials

Geun Ho Ahn
Matin Amani
2018

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
2018

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
2018

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
2018

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
2018

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
2018

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...

BPN825: Direct On-Chip Digital Optical Synthesizer (DODOS)

Jean-Etienne Tremblay
Guan-Lin Su
Kyungmok Kwon
2018

The advent of precise microwave frequency synthesis in the 1940’s enabled a disruptive revolution in the capabilities enabled by microwave technology, including wireless and wireline communications, RADAR, electronic warfare, and atomic sensors and timing technology. It is envisioned that the DODOS program will advance a similar transformative revolution based on ubiquitous optical frequency synthesis technology. Laboratory-scale optical frequency synthesis was successfully realized in 1999 with the invention of self-referenced optical frequency combs based on femto-second pulse-...

BPN790: Two-Dimensional Materials-Based Aerogel on Low-Power Microheater Platform for Gas Sensing Application

Siyi Cheng
David Gardner
2018

There remains a strong need for miniaturized, low power gas sensors that can be deployed in wireless applications for improved environmental protection, health and safety. Aerogels have attracted significant attention in recent years due to their extremely low density, high surface area, low thermal conductivity, weak dielectric permittivity, and high stability. For gas sensing applications, two-dimensional materials offer the highest possible surface area for gas interaction, leading to high sensitivity. However, when materials are integrated into a sensor device, the surface area...

BPN835: Silicon Carbide Passivated Electrode for Thermionic Energy Conversion

Steven R. DelaCruz
Zhongtao Wang
2018

In thermionic energy converters (TECs), electrons emitted from a hot electrode (emitter) into a vacuum gap are harvested by a cooler electrode (collector), and then return to the emitter, delivering power to an external load. In this process, TECs convert heat directly into electricity and have the potential to achieve high efficiencies comparable to those of conventional heat engines. We have initiated a collaborative project to develop a microfabricated, close-gap thermionic energy converter that utilizes heat from a combustion source. Potential applications include residential...

BPN889: Fabrication and Self-Assembly of Microstructured Scaffolds for Living Material

Wei Li
2018

Design, synthesize, assemble, and characterize hard-soft hybrid composites that resemble brick-and- mortar structure of nacre, but that can switch between being porous and flexible to impermeable, stiff, and strong in response to environmental cues.

Project end date: 01/25/19