National Technology & Engineering Solutions of Sandia, LLC

Sandia Corporation

Purdue Research Foundation

Parker-Hannifin Corporation

Stephen Wayne Howell

David W Peters

Thomas Edwin Beechem, Iii

Isaac Ruiz

Paul Davids

Michael Goldflam

David R Wheeler

Fred E Regnier

Shawn Matthew Dirk

Anna Tauke-Pedretti

Alex Robinson

Michael P Siegal

Richard Karl Harrison

Ronald George Reifenberger

Curtis D Mowry

William M Cost

Jeffrey B Martin

Joshua J Whiting

Halina Dorota Inerowicz

Taisuke Ohta

Kazi Zulfiqur Ali Hassan

A monolithically integrated, tunable infrared pixel comprises a combined broadband detector and graphene-enabled tunable metasurface filter that operate as a single solid-state device with no moving parts. Functionally, tunability results from the plasmonic properties of graphene that are acutely dependent upon the carrier concentration within the infrared. Voltage induced changes in graphene's carrier concentration can be leveraged to change the metasurface filter's transmission thereby altering the 'colors' of light reaching the broadband detector and hence its spectral responsivity. The invention enables spectrally agile infrared detection with independent pixel-to-pixel spectral tunability.

Tunable infrared pixels having unpatterned graphene layer and conductive metasurface

A radiation field is detected or imaged using one or more junction devices in which a two-dimensional conductor layer is capacitively coupled to a semiconductor absorber layer. In the junction devices, pixel-level amplification and read-out are accomplished through the photogating of the devices by absorption within the absorber layer while it is in a state of deep depletion. When the two-dimensional conductor is graphene, we refer to a device operating in that manner as a deeply depleted graphene-oxide-semiconductor (DGOS) detector.

Radiation detector using a graphene amplifier layer

An actively tunable optical filter can control the amplitude of reflected infrared light. The filter exploits the dependence of the excitation energy of plasmons in a continuous and unpatterned sheet of graphene, on the Fermi-level, which can be controlled by conventional electrostatic gating. An exemplary filter enables simultaneous modification of two distinct spectral bands whose positions are dictated by the device geometry and graphene plasmon dispersion. Within these bands, the reflected amplitude can be varied by over 15% and resonance positions can be shifted by over 90 cm. Electromagnetic simulations verify that tuning arises through coupling of incident light to graphene plasmons by a nanoantenna grating structure. Importantly, the tunable range is determined by a combination of graphene properties, device structure, and the surrounding dielectrics, which dictate the plasmon dispersion. Thus, the underlying design is applicable across a broad range of infrared frequencies.

Tunable graphene-based infrared reflectance filter having patterned nanoantenna layer and unpatterned graphene layer

The integration of bilayer graphene with an absorption enhancing sub-wavelength antenna provides an infrared photodetector capable of real-time spectral tuning without filters at nanosecond timescales.

Sub-wavelength antenna enhanced bilayer graphene tunable photodetector

A portable analytical system for detecting organic chemicals in water comprising a miniature preconcentrator and a SAW detector, the latter being characterized by a nanoporous carbon coating that provides improved response compared to prior art polymer coatings, particularly when detecting low concentrations of trihalomethane chemicals, such as chloroform and bromoform.

Portable analytical system for detecting organic chemicals in water

Method and device for detection of analytes, particularly biohazards. A microarray containing immobilized sensing molecules captures complementary analytes on a redundant patterned substrate. Pattern analysis is performed using a computer algorithm.

Microarrays for analyte detection

Methods are described for the electrochemical assembly of organic molecules on silicon, or other conducting or semiconducting substrates, using iodonium salt precursors. Iodonium molecules do not assemble on conducting surfaces without a negative bias. Accordingly, the iodonium salts are preferred for patterning applications that rely on direct writing with negative bias. The stability of the iodonium molecule to acidic conditions allows them to be used with standard silicon processing. As a directed assembly process, the use of iodonium salts provides for small features while maintaining the ability to work on a surface and create structures on a wafer level. Therefore, the process is amenable for mass production. Furthermore, the assembled monolayer (or multilayer) is chemically robust, allowing for subsequent chemical manipulations and the introduction of various molecular functionalities for various chemical and biological applications.

Electrochemical assembly of organic molecules by the reduction of iodonium salts

Growing community of inventors

Albuquerque, NM, United States of America

Stephen Wayne Howell