Related Experiment Video
Updated: Jul 9, 2026
12:08
Fabrication of High Contrast Gratings for the Spectrum Splitting Dispersive Element in a Concentrated Photovoltaic System
Published on: July 18, 2015
Broadband antireflection gratings fabricated upon silicon substrates
Optics Letters
|December 15, 2007
Summary
Researchers created a subwavelength structured (SWS) surface on silicon, significantly reducing reflectivity to 0.5% across a broad wavelength range. This advanced nanostructure offers potential for improved optical applications.
Area of Science:
- Materials Science
- Nanotechnology
- Optics
Background:
- Silicon's high reflectivity limits its use in optical devices.
- Subwavelength structures (SWS) offer a method to control light-matter interactions.
Purpose of the Study:
- To fabricate and characterize a two-dimensional SWS surface on a silicon substrate.
- To evaluate the broadband anti-reflective properties of the fabricated SWS surface.
Main Methods:
- Fabrication using electron beam lithography and SF(6) fast atom beam etching.
- Characterization of surface morphology, including conical profile, 150 nm period, and 350 nm groove depth.
- Measurement of reflectivity from 200-2500 nm and as a function of incident angle using HeNe laser.
Main Results:
- Achieved a significant reduction in reflectivity from 54.7% to 0.5% at 400 nm.
- Demonstrated broadband anti-reflective performance across the 200-2500 nm spectrum.
- Analyzed the angular dependence of reflectivity.
Conclusions:
- The fabricated SWS surface exhibits excellent broadband anti-reflective properties.
- The SWS surface on silicon is a promising candidate for advanced optical applications requiring minimal reflection.
