Featured Research

from universities, journals, and other organizations

Blackest Black Ever: Ultra-thin Material Absorbs Almost 100% Of Light

Date:
July 2, 2009
Source:
Leiden University
Summary:
It appears to be a paradox: ultra-thin material that absorbs all incident light. Nonetheless, it does exist. Researchers have demonstrated that at a thickness of 4.5 nanometer niobiumnitride (NbN) is ultra-absorbent. They have recorded a light absorption of almost 100%, while the best light absorption to date was 50%. This research brings the ideal light detector a step closer.

How much light is reflected and how much is absorbed depends on two factors: the angle at which the light falls onto the material, and the polarisation (the direction of oscillation) of the light.
Credit: Image courtesy of Leiden University

It appears to be a paradox: ultra-thin material that absorbs all the incident light. Nonetheless, it does exist.

Ideal light detector

Two researchers, Eduard Driessen, MSc, and Dr Michiel de Dood, have demonstrated that at a thickness of 4.5 nanometer niobiumnitride (NbN) is ultra-absorbent. They have recorded a light absorption of almost 100%, while the best light absorption to date was 50%. This research brings the ideal light detector a step closer.

A cell made of this material can already collect light and convert it into an electrical signal. The high number of downloads indicates that this research is very special.

Angles and polarisation

Materials that could potentially absorb a lot of light have the problem that they reflect the incident light; they are generally very good mirrors. But how much light is reflected and how much is absorbed depends on two factors: the angle at which the light falls onto the material, and the polarisation (the direction of oscillation) of the light. Light has two kinds of polarisation: s and p polarisation.

Polaroid sunglasses make good use of this characteristic. The light absorption of a thin slice of NbN is at its maximum if the light falls on it at an angle of 35 and only consists of s-polarised light. The absorption achieved is then 94%. The p-polarised light is reflected in full. At an angle of 46 the absorption for both polarisation directions is 80%, which is still extremely good.

Applications

This discovery gave Driessen and De Dood the idea for building a special detector. They want to use this detector to view individual light particles, photons. To date this has been very difficult because the absorption was not high enough. The most important part of the detector is a lattice of ultra-absorbent NbN filaments. When an s-light particle falls on the lattice, it is absorbed. A p-particle is reflected. This p-particle can then in turn be collected by a second detector so that all the light is detected.

Calculations show that the wavelength (colour) of the light particle has hardly any influence. The detector can therefore also be used for particles with completely different wavelengths, such as detection systems for telecommunications and infra-red equipment.

The research is being carried out in collaboration with the TU Delft and will be part-funded by the Netherlands Organisation for Scientific Research (NWO) and the Foundation for Fundamental Materials Research (FOM).


Story Source:

The above story is based on materials provided by Leiden University. Note: Materials may be edited for content and length.


Journal Reference:

  1. E. F. C. Driessena and M. J. A. de Dood. The perfect absorber. Applied Physics Letters, Online April 29, 2009 DOI: 10.1063/1.3126062

Cite This Page:

Leiden University. "Blackest Black Ever: Ultra-thin Material Absorbs Almost 100% Of Light." ScienceDaily. ScienceDaily, 2 July 2009. <www.sciencedaily.com/releases/2009/06/090630082647.htm>.
Leiden University. (2009, July 2). Blackest Black Ever: Ultra-thin Material Absorbs Almost 100% Of Light. ScienceDaily. Retrieved April 25, 2014 from www.sciencedaily.com/releases/2009/06/090630082647.htm
Leiden University. "Blackest Black Ever: Ultra-thin Material Absorbs Almost 100% Of Light." ScienceDaily. www.sciencedaily.com/releases/2009/06/090630082647.htm (accessed April 25, 2014).

Share This



More Matter & Energy News

Friday, April 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Next Stop America for France's TGV?

Next Stop America for France's TGV?

Reuters - Business Video Online (Apr. 24, 2014) General Electric keeps quiet on reports it's in talks to buy French turbine and train maker Alstom. Ivor Bennett reports on what could be an embarrassing rumour for the French government, with business-friendly reforms proving a hard sell. Video provided by Reuters
Powered by NewsLook.com
Raw: Obama Plays Soccer With Japanese Robot

Raw: Obama Plays Soccer With Japanese Robot

AP (Apr. 24, 2014) President Obama briefly played soccer with a robot during his visit to Japan on Thursday. The President has been emphasizing technology along with security concerns during his visit. (April 24) Video provided by AP
Powered by NewsLook.com
Obama Encourages Japanese Student-Scientists

Obama Encourages Japanese Student-Scientists

AP (Apr. 24, 2014) President Obama spoke with student innovators in Japan and urged them to take part in increased opportunities for student exchanges with the US. (April 24) Video provided by AP
Powered by NewsLook.com
UN Joint Mission Starts Removing Landmines in Cyprus

UN Joint Mission Starts Removing Landmines in Cyprus

AFP (Apr. 23, 2014) The UN mission in Cyprus (UNFICYP) led a mine clearance demonstration on Wednesday in the UN-controlled buffer zone where demining operations are being conducted near the Cypriot village of Mammari. Duration: 01:00 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins