Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > Moth-Inspired Nanostructures Take the Color Out of Thin Films

The nanostructures limit the amount of light reflected at the thin film interface.
The nanostructures limit the amount of light reflected at the thin film interface.

Abstract:
"Antireflection Effects at Nanostructured Material Interfaces and the Suppression of Thin-Film Interference"

Authors: Qiaoyin Yang, Xu A. Zhang, Abhijeet Bagal, Wei Guo and Chih-Hao Chang, North Carolina State University

Published: May 16, Nanotechnology

DOI: 10.1088/0957-4484/24/23/235202

Abstract: Thin-film interference is a well-known effect, and it is commonly observed in the colored appearance of many natural phenomena. Caused by the interference of light reflections from the interfaces of thin material layers, such interference effects can lead to wavelength and angle-selective behavior in thin-film devices. In this work, we describe the use of interfacial nanostructures to eliminate interference effects in thin films. Using the same principle inspired by the moth-eye structures, this approach creates an effective medium where the index is gradually varying between the neighboring materials. We present the fabrication process for such nanostructures at a polymer-silicon interface, and experimentally demonstrate its effectiveness in suppressing thin-film interference. The principle demonstrated in this work can lead to enhanced efficiency and reduce wavelength/angle sensitivity in multilayer optoelectronic devices.

Moth-Inspired Nanostructures Take the Color Out of Thin Films

Raleigh, NC | Posted on May 17th, 2013

Inspired by the structure of moth eyes, researchers at North Carolina State University have developed nanostructures that limit reflection at the interfaces where two thin films meet, suppressing the "thin-film interference" phenomenon commonly observed in nature. This can potentially improve the efficiency of thin-film solar cells and other optoelectronic devices.

Thin-film interference occurs when a thin film of one substance lies on top of a second substance. For example, thin-film interference is what causes the rainbow sheen we see when there is gasoline in a puddle of water.

Gasoline is transparent, but some light is still reflected off of its surface. Similarly, some of the light that passes through the gasoline is reflected off the underlying surface of the water where the two substances interface, or meet. Because the light reflected off the water has to pass back through the gasoline, it takes a slightly different optical path than the light that was reflected off the surface of the gasoline. The mismatch of these optical path "lengths" is what creates the rainbow sheen - and that phenomenon is thin-film interference.

Thin-film interference is a problem for devices that use multiple layers of thin films, like thin-film solar cells, because it means that some wavelengths of light are being reflected - or "lost" - at every film interface. The more thin films a device has, the more interfaces there are, and the more light is lost.

"We were inspired by the surface structure of a moth's eye, which has evolved so that it doesn't reflect light," says Dr. Chih-Hao Chang, an assistant professor of mechanical and aerospace engineering at NC State and co-author of a paper on the research. "By mimicking that concept, we've developed a nanostructure that significantly minimizes thin-film interference."

The nanostructures are built into thin films that will have a second thin film placed on top of them. The nanostructures are an extension of the thin film beneath them, and resemble a tightly-packed forest of thin cones. These nanostructures are "interfacial," penetrating into whatever thin film is layered on top of them - and limiting the amount of light reflected at that interface. Chang's team found that the an interface featuring the interfacial nanostructures reflects 100 times less light than an interface of thin films without the nanostructures.

"Our next steps are to design a solar device that takes advantage of this concept and to determine how we can scale it up for commercial applications," Chang says.

The paper, "Antireflection Effects at Nanostructured Material Interfaces and the Suppression of Thin-Film Interference," was published online May 15 in the journal Nanotechnology. Lead author of the paper is former NC State graduate student Qiaoyin Yang. Co-authors are Chang and NC State Ph.D. students Xu A. Zhang, Abhijeet Bagal and Wei Guo. The research was supported by a NASA Early Career Faculty Award and the National Science Foundation's ASSIST Engineering Research Center at NC State.

####

For more information, please click here

Contacts:
Matt Shipman

919-515-6386

Dr. Chih-Hao Chang
919.513.7968

Copyright © North Carolina State University

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related Links

Download the paper, “Antireflection Effects at Nanostructured Material Interfaces and the Suppression of Thin-Film Interference.”:

Related News Press

News and information

ANU invention to inspire new night-vision specs December 7th, 2016

Arrowhead Pharmaceuticals to Webcast Fiscal 2016 Year End Results December 7th, 2016

Journal Nanotechnology Progress International (JONPI), newest edition out December 7th, 2016

In IEDM 2016 Keynote, Leti CEO Says ‘Hyperconnectivity’, Human-focused Research and the IOT Promise Profound, Positive Changes December 7th, 2016

Thin films

ANU invention to inspire new night-vision specs December 7th, 2016

Govt.-Legislation/Regulation/Funding/Policy

Physicists decipher electronic properties of materials in work that may change transistors December 6th, 2016

Construction of practical quantum computers radically simplified: Scientists invent ground-breaking new method that puts quantum computers within reach December 5th, 2016

Shape matters when light meets atom: Mapping the interaction of a single atom with a single photon may inform design of quantum devices December 4th, 2016

Research Study: MetaSOLTM Shatters Solar Panel Efficiency Forecasts with Innovative New Coating: Coating Provides 1.2 Percent Absolute Enhancement to Triple Junction Solar Cells December 2nd, 2016

Optical computing/Photonic computing

Shape matters when light meets atom: Mapping the interaction of a single atom with a single photon may inform design of quantum devices December 4th, 2016

New method for analyzing crystal structure: Exotic materials called photonic crystals reveal their internal characteristics with new method November 30th, 2016

Novel silicon etching technique crafts 3-D gradient refractive index micro-optics November 28th, 2016

Single photon converter -- a key component of quantum internet November 28th, 2016

Discoveries

ANU invention to inspire new night-vision specs December 7th, 2016

Leti IEDM 2016 Paper Clarifies Correlation between Endurance, Window Margin and Retention in RRAM for First Time: Paper Presented at IEDM 2016 Offers Ways to Reconcile High-cycling Requirements and Instability at High Temperatures in Resistive RAM December 6th, 2016

Tokyo Institute of Technology research: 3D solutions to energy savings in silicon power transistors December 6th, 2016

Physicists decipher electronic properties of materials in work that may change transistors December 6th, 2016

Announcements

ANU invention to inspire new night-vision specs December 7th, 2016

Arrowhead Pharmaceuticals to Webcast Fiscal 2016 Year End Results December 7th, 2016

Journal Nanotechnology Progress International (JONPI), newest edition out December 7th, 2016

In IEDM 2016 Keynote, Leti CEO Says ‘Hyperconnectivity’, Human-focused Research and the IOT Promise Profound, Positive Changes December 7th, 2016

Interviews/Book Reviews/Essays/Reports/Podcasts/Journals/White papers

ANU invention to inspire new night-vision specs December 7th, 2016

Journal Nanotechnology Progress International (JONPI), newest edition out December 7th, 2016

Tokyo Institute of Technology research: 3D solutions to energy savings in silicon power transistors December 6th, 2016

Physicists decipher electronic properties of materials in work that may change transistors December 6th, 2016

Energy

Research Study: MetaSOLTM Shatters Solar Panel Efficiency Forecasts with Innovative New Coating: Coating Provides 1.2 Percent Absolute Enhancement to Triple Junction Solar Cells December 2nd, 2016

Deep insights from surface reactions: Researchers use Stampede supercomputer to study new chemical sensing methods, desalination and bacterial energy production December 2nd, 2016

Throwing new light on printed organic solar cells December 1st, 2016

Physics, photosynthesis and solar cells: Researchers combine quantum physics and photosynthesis to make discovery that could lead to highly efficient, green solar cells November 30th, 2016

Aerospace/Space

Infrared instrumentation leader secures exclusive use of Vantablack coating December 5th, 2016

New records set up with 'Screws of Light' November 20th, 2016

Keep it Clean: Leti and French Partners to Test ‘Smart’ Antibacterial Surfaces in Space: Matiss Experiment Designed to Measure Most Effective Material for Cleaning International Space Station and Is Expected to Provide Earth-bound Applications November 15th, 2016

Nanocellulose in medicine and green manufacturing: American University professor develops method to improve performance of cellulose nanocrystals November 7th, 2016

Photonics/Optics/Lasers

ANU invention to inspire new night-vision specs December 7th, 2016

Shape matters when light meets atom: Mapping the interaction of a single atom with a single photon may inform design of quantum devices December 4th, 2016

Controlled electron pulses November 30th, 2016

New method for analyzing crystal structure: Exotic materials called photonic crystals reveal their internal characteristics with new method November 30th, 2016

Solar/Photovoltaic

Research Study: MetaSOLTM Shatters Solar Panel Efficiency Forecasts with Innovative New Coating: Coating Provides 1.2 Percent Absolute Enhancement to Triple Junction Solar Cells December 2nd, 2016

Throwing new light on printed organic solar cells December 1st, 2016

Physics, photosynthesis and solar cells: Researchers combine quantum physics and photosynthesis to make discovery that could lead to highly efficient, green solar cells November 30th, 2016

'Back to the Future' inspires solar nanotech-powered clothing November 15th, 2016

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project