Blackest Black Ever: Ultra-thin Material Absorbs Almost 100% Of Light
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.
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 35º 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 46º the absorption for both polarisation directions is 80%, which is still extremely good.
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).
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