Ultra-black nickel-phosphorus alloy optical absorber

Comprehensive characterization of broadband ultralow reflectance of a porous nickel–phosphorus black surface by numerical simulation

“…We modeled the geometry and composition of a porous NiP black surface by referring to the published reports [1,4,[14][15][16][18][19][20]24]. On the basis of electron microscopic studies of porous NiP black surfaces [15,16,18,20], we assumed a simple surface morphology of conical pores with an absorption layer on a metal substrate, as shown in Fig.…”

“…Currently available broadband low-reflectance materials include gold black [7]; carbon nanotubes (CNTs) [8][9][10][11][12][13]; black nickels [3,4,14], including porous nickelphosphorus (NiP) black surfaces [1,[15][16][17][18][19][20]; and black paint. Antireflection textured surfaces [21][22][23] are also categorized as low-reflectance surfaces; the texture of a nondispersive material provides nearly perfect transmission rather than high absorption [23].…”

Fabrication of hard-coated optical absorbers with microstructured surfaces using etched ion tracks: Toward broadband ultra-low reflectance

“…4 as the solid curve for the 2.96-aspect-ratio model (for the 11-lm-opening sample) and as the dashed curve for the 2.4-aspect-ratio model (for the 33-lm-opening sample). The simulated spectral reflectance was around 0.1% even for the aspect ratio below 3, which is comparable to the reflectance of VACNT black [8,[10][11][12][13] or NiP black surface [24,25].…”

“…Recently, the authors have investigated the mechanism of ultra-low reflectance from nickel phosphorous (NiP) black surface [24], which is one of the darkest materials in the visible to near infrared range of wavelengths [25,26]. NiP black surfaces have microporous morphology of conically shaped pits with an optical absorption layer of oxidized nickel on them, where the incident light experiences multiple reflections, thus effectively enhancing the light absorption.…”

Cryogenic Solar Absolute Radiometer - CSAR

“…The cavities are electro-formed from copper; the external surfaces are gold plated and the internal surfaces are treated with a black coating formed using a plating technique (Kodama et al 1990). The reflectance of the black has been measured at NPL over the range 0.3 p2n to 54 p/n and is predominantly a diffuse reflector.…”