Search
Menu
Gentec Electro-Optics Inc   - Measure With Gentec Accuracy LB

Doping Process Increases Conductivity, Transparency of Graphene

Facebook X LinkedIn Email
An interdisciplinary team of researchers from Columbia University and Sungkyungkwan University (South Korea) has introduced a clean technique to dope graphene via a charge-transfer layer made of low-impurity tungsten oxyselenide (TOS).

The team generated the new “clean” layer by oxidizing a single atomic layer of another 2D material, tungsten selenide. When team members layered TOS on top of the graphene, they found that it left the graphene riddled with electricity-conducting holes. The holes could be fine-tuned to better control the materials’ electricity-conducting properties by adding a few atomic layers of tungsten selenide between the TOS and graphene.

The researchers found that graphene’s electrical mobility, or how easily charges move through it, was higher with their new doping method than previous attempts. Adding tungsten selenide spacers further increased the mobility, to the point where the effect of the TOS became negligible. This left mobility to be determined by the intrinsic properties of graphene itself.

This combination of high doping and high mobility gives graphene greater electrical conductivity than that of highly conductive metals, including copper and gold.

As the ability of the doped graphene to conduct electricity improved, the transparency of the graphene also increased, due to Pauli blocking — a phenomenon where charges manipulated by doping block the material from absorbing light.

The TOS-doped graphene used in research by an international team is highly conductive but absorbs very little of the infrared light in the resonator — a combination of properties that makes this material unique and promising for opto-electronic applications. Courtesy of Ipshita Datta, Lipson Nanophotonics Group, Columbia University.
The TOS-doped graphene used in research by an international team is highly conductive but absorbs very little of the infrared light in the resonator — a combination of properties that makes this material unique and promising for opto-electronic applications. Courtesy of Ipshita Datta, Lipson Nanophotonics Group, Columbia University.
The researchers reported that at the infrared wavelengths used in telecommunications, the graphene became more than 99% transparent.

CASTECH INC - High Precision CNC Polished Aspherical Lenses

Achieving a high rate of transparency and conductivity is crucial to the ability to move information through light-based photonic devices; if too much light is absorbed, information becomes lost. The team found a much smaller loss for TOS-doped graphene than for other conductors, which suggested that the new method could hold potential for next-generation ultra-efficient photonic devices.

One promising direction for the research involves altering graphene’s electronic and optical properties by changing the pattern of the TOS, and imprinting electrical circuits directly on the graphene itself. The research team is also working to integrate the doped material into novel photonic devices, with potential applications in transparent electronics, telecommunications systems, and quantum computers.

The research was published in Nature Electronics (www.doi.org/10.1038/s41928-021-00657-y).

Published: November 2021
Glossary
transparency
An image affixed to a transparent photographic film or plate by photographic, printing or chemical methods. It may be viewed by transmitted light.
doping
The addition of impurities to another substance, usually solid, in a controlled manner that produces desired properties. Silicon doping with small amounts of other semimetallic elements increases the number of electrical carriers.
infrared
Infrared (IR) refers to the region of the electromagnetic spectrum with wavelengths longer than those of visible light, but shorter than those of microwaves. The infrared spectrum spans wavelengths roughly between 700 nanometers (nm) and 1 millimeter (mm). It is divided into three main subcategories: Near-infrared (NIR): Wavelengths from approximately 700 nm to 1.4 micrometers (µm). Near-infrared light is often used in telecommunications, as well as in various imaging and sensing...
nano
An SI prefix meaning one billionth (10-9). Nano can also be used to indicate the study of atoms, molecules and other structures and particles on the nanometer scale. Nano-optics (also referred to as nanophotonics), for example, is the study of how light and light-matter interactions behave on the nanometer scale. See nanophotonics.
nanophotonics
Nanophotonics is a branch of science and technology that explores the behavior of light on the nanometer scale, typically at dimensions smaller than the wavelength of light. It involves the study and manipulation of light using nanoscale structures and materials, often at dimensions comparable to or smaller than the wavelength of the light being manipulated. Aspects and applications of nanophotonics include: Nanoscale optical components: Nanophotonics involves the design and fabrication of...
optoelectronics
Optoelectronics is a branch of electronics that focuses on the study and application of devices and systems that use light and its interactions with different materials. The term "optoelectronics" is a combination of "optics" and "electronics," reflecting the interdisciplinary nature of this field. Optoelectronic devices convert electrical signals into optical signals or vice versa, making them crucial in various technologies. Some key components and applications of optoelectronics include: ...
Research & TechnologyOpticstransparencygraphenedopingMaterialstungsten selenidedopedtungsten oxyselenideColumbia UniversitySungkyungkwan Universityconductivityelectronselectron holeinfrared lightinfraredopto-electronicsAmericassiliconsilicon photonicsnanonanophotonicsMichal LipsonoptoelectronicsTechnology News

We use cookies to improve user experience and analyze our website traffic as stated in our Privacy Policy. By using this website, you agree to the use of cookies unless you have disabled them.