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Physical Measurement Laboratory / Applied Physics Division

Quantitative Nanostructure Characterization Group

Projects/Programs

Displaying 1 - 14 of 14
Schematics and diffraction patterns

Aberration-corrected scanning transmission electron microscopy

Ongoing
As devices continue to become smaller, more complex, and more highly integrated, atomic scale measurements of their structure, chemistry, strain, and electric field are increasingly crucial for device design, reliability, and optimization. The aberration-corrected scanning transmission electron
A time series of a MoS2 flake exposed to increasing time under electrical stress shows the growth of defects denoted with red and yellow areas over time. S= source and D = drain electrode.

Evaluation of 2D and WBG Material Quality Toward Device Reliability

Ongoing
Two-dimensional (2D) and wide band gap (WBG) materials are some of the latest materials classes having the potential to be transformative because of their high carrier mobilities, tunable bandgap, and atomic-scale film thicknesses. Unexpected degradation and failure in device performance is often
extreme atom probe tomography illustration

Extreme Atom Probe Tomography

Ongoing
Sub-nanometer-resolved 3-D chemical mapping of any atom in any solid continues to be an imperative goal of materials research. If reduced to practice, it would have profound scientific, engineering, and economic impacts on U.S. industries collectively worth hundreds of billions of dollars. Such
Electron microscopy images

GaN Nanowire Growth

Ongoing
Selective epitaxy: We have demonstrated that the diameter and placement of nanowires can be controlled by using silicon nitride (SiNx) masks on top of MBE-grown buffer layers (see figure). With electron beam lithography, several patterns with 3 mm die size that provide over 100,000 controlled
nanowires

GaN Nanowire Metrology and Applications

Ongoing
GaN Nanowire LEDs: Our selective epitaxy methods and dopant characterization techniques have enabled fabrication of arrays of nanowire LEDs with controlled location and spatial layout. This development is complemented by modeling of the carrier flow and recombination. These LEDs were combined to
Schematic illustration of the integrated near-field optoelectronic (INFO) probe showing light emission, microwave reflection lines for measuring specimen conductivity and/or magnetization, and simultaneous contact topography feedback.  

Integrated Near-field Optoelectronic (INFO) Scanning Probe

Ongoing
In a collaboration between the Nanoelectromagnetics Project and the Quantitative Imaging Project, we have fabricated and tested a GaN nanowire mounted on an AFM tip as a near-field scanning microwave microscopy (NSMM ) tip (see Fig. 2(a) below ). A tungsten atomic layer deposition (ALD) coating
(a) Schematic of a near-field scanning microwave microscope (NSMM). (b) NSMM images of a perovskite PV sample, (c) NSMM MoS2 back-gate device, (d) Spatial imaging of excited spin wave modes.

Nanoelectromagnetics

Ongoing
The primary goal of this program is metrology that enables advanced nanoscale device (including electronics, spintronics, and life science) development. Based on current trends in electronics, we are focusing on metrology for two classes of devices: (1) nanoscale devices utilizing and exploring new
nanopillars

Nanophononic Metamaterials for Thermoelectrics

Ongoing
About 68 % of the energy produced in the United States is wasted as heat lost to the environment. About a quarter of this lost heat is present at temperature gradients suitable for recovery with thermoelectric devices, which use the ability of semiconductors to generate electricity directly from

Subspace-Informed Deep Learning Solutions for Nanoscale Microscopy

Ongoing
Cutting-edge nanoscale microscopy techniques such as near-field scanning microwave microscopy (NSMM) and atom probe tomography (APT) enable a multi-dimensional virtual representation of an artifact to be constructed from a set of experimental measurements. These imaging techniques, which are
solar simulator graph

Super-Continuum Laser Solar Simulator

Completed
The design of the super-continuum solar simulator is shown below. Light is produced from 450 nm to 2400 nm in sub-nanosecond pulses at a repetition rate of 80 MHz. The total irradiance is sufficient to illuminate a 1 cm 2 cell at more than 1-sun. Initial tests have confirmed that solar cells respond