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

Particle Works creates range of high performance quantum dots February 23rd, 2017

GLOBALFOUNDRIES Announces Availability of 45nm RF SOI to Advance 5G Mobile Communications: Optimized RF features deliver high-performance solutions for mmWave beam forming applications in 5G smartphones and base stations February 22nd, 2017

EmTech Asia breaks new barriers with potential applications of space exploration with NASA and MIT February 22nd, 2017

JPK selects compact tensile stage from Deben for their NanoWizard® AFM platform to broaden capabilities for materials characterisation February 22nd, 2017

Thin films

Dual-function nanorod LEDs could make multifunctional displays February 11th, 2017

NREL research pinpoints promise of polycrystalline perovskites February 8th, 2017

New material with ferroelectricity and ferromagnetism may lead to better computer memory December 21st, 2016

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

Govt.-Legislation/Regulation/Funding/Policy

Molecular phenomenon discovered by advanced NMR facility: Cutting edge technology has shown a molecule self-assembling into different forms when passing between solution state to solid state, and back again - a curious phenomenon in science - says research by the University of Wa February 22nd, 2017

'Lossless' metamaterial could boost efficiency of lasers and other light-based devices February 20th, 2017

Engineers shrink microscope to dime-sized device February 17th, 2017

Francis Alexander Named Deputy Director of Brookhaven Lab's Computational Science Initiative February 16th, 2017

Optical computing/Photonic computing

'Lossless' metamaterial could boost efficiency of lasers and other light-based devices February 20th, 2017

Liquid metal nano printing set to revolutionize electronics: Creating integrated circuits just atoms thick February 18th, 2017

Research opens door to smaller, cheaper, more agile communications tech February 16th, 2017

1,000 times more efficient nano-LED opens door to faster microchips February 5th, 2017

Discoveries

Molecular phenomenon discovered by advanced NMR facility: Cutting edge technology has shown a molecule self-assembling into different forms when passing between solution state to solid state, and back again - a curious phenomenon in science - says research by the University of Wa February 22nd, 2017

Tiny nanoclusters could solve big problems for lithium-ion batteries February 21st, 2017

Oxford Instruments announces Dr Brad Ramshaw of Cornell University, as winner of the 2017 Lee Osheroff Richardson Science Prize February 20th, 2017

Breakthrough with a chain of gold atoms: In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport February 20th, 2017

Announcements

Particle Works creates range of high performance quantum dots February 23rd, 2017

GLOBALFOUNDRIES Announces Availability of 45nm RF SOI to Advance 5G Mobile Communications: Optimized RF features deliver high-performance solutions for mmWave beam forming applications in 5G smartphones and base stations February 22nd, 2017

EmTech Asia breaks new barriers with potential applications of space exploration with NASA and MIT February 22nd, 2017

JPK selects compact tensile stage from Deben for their NanoWizard® AFM platform to broaden capabilities for materials characterisation February 22nd, 2017

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

Molecular phenomenon discovered by advanced NMR facility: Cutting edge technology has shown a molecule self-assembling into different forms when passing between solution state to solid state, and back again - a curious phenomenon in science - says research by the University of Wa February 22nd, 2017

Tiny nanoclusters could solve big problems for lithium-ion batteries February 21st, 2017

Breakthrough with a chain of gold atoms: In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport February 20th, 2017

'Lossless' metamaterial could boost efficiency of lasers and other light-based devices February 20th, 2017

Energy

Strem Chemicals and Dotz Nano Ltd. Sign Distribution Agreement for Graphene Quantum Dots Collaboration February 21st, 2017

'Lossless' metamaterial could boost efficiency of lasers and other light-based devices February 20th, 2017

In-cell molecular sieve from protein crystal February 14th, 2017

NREL research pinpoints promise of polycrystalline perovskites February 8th, 2017

Aerospace/Space

EmTech Asia breaks new barriers with potential applications of space exploration with NASA and MIT February 22nd, 2017

Particles from outer space are wreaking low-grade havoc on personal electronics February 19th, 2017

New method improves accuracy of imaging systems February 8th, 2017

National Space Society's Space Settlement Summit Draws Industry Leaders February 4th, 2017

Photonics/Optics/Lasers

'Lossless' metamaterial could boost efficiency of lasers and other light-based devices February 20th, 2017

Liquid metal nano printing set to revolutionize electronics: Creating integrated circuits just atoms thick February 18th, 2017

Research opens door to smaller, cheaper, more agile communications tech February 16th, 2017

1,000 times more efficient nano-LED opens door to faster microchips February 5th, 2017

Solar/Photovoltaic

Strem Chemicals and Dotz Nano Ltd. Sign Distribution Agreement for Graphene Quantum Dots Collaboration February 21st, 2017

'Lossless' metamaterial could boost efficiency of lasers and other light-based devices February 20th, 2017

Material can turn sunlight, heat and movement into electricity -- all at once: Extracting energy from multiple sources could help power wearable technology February 9th, 2017

NREL research pinpoints promise of polycrystalline perovskites February 8th, 2017

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