title: A novel silicon nanotips antireflection surface for the micro Sun sensor.
abstract: We have developed a new technique to fabricate an antireflection surface using silicon nanotips for use on a micro Sun sensor for Mars rovers. We have achieved randomly distributed nanotips of radii spanning from 20 to 100 nm and aspect ratio of approximately 200 using a two-step dry etching process. The 30 degrees specular reflectance at the target wavelength of 1 microm is only about 0.09%, nearly 3 orders of magnitude lower than that of bare silicon, and the hemispherical reflectance is approximately 8%. When the density and aspect ratio of these nanotips are changed, a change in reflectance is demonstrated. When surfaces are covered with these nanotips, the critical problem of ghost images that are caused by multiple internal reflections in a micro Sun sensor was solved.
authors.affiliation: California Institute of Technology, 1200 California Boulevard, Pasadena, CA 91125, USA. Choonsup.Lee@jpl.nasa.gov
authors.forename: Choonsup
authors.initials: C
authors.lastname: Lee
authors.forename: Sam Y
authors.initials: SY
authors.lastname: Bae
authors.forename: Sohrab
authors.initials: S
authors.lastname: Mobasser
authors.forename: Harish
authors.initials: H
authors.lastname: Manohara
mesh_terms: D003460:Crystallization / Q000379:methods*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008027:Light; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D036103:Nanotechnology / Q000295:instrumentation* / Q000379:methods; D010781:Photography / Q000295:instrumentation* / Q000379:methods; D012542:Scattering, Radiation; D012825:Silicon / Q000737:chemistry*; D016082:Solar System; D014159:Transducers
chemical_list: D012825:Silicon