Silicon colors: spectral selective perfect light absorption in single layer silicon films on aluminum surface and its thermal tunability.

Using two most abundant materials in nature: silicon and aluminum, spectral selective perfect light absorption in single layer silicon films on aluminum surface is demonstrated. Perfect light absorption is achieved due to the critical coupling of incident optical wave to the second order resonance mode of the optical cavity made of a thin silicon film on aluminum surface. Spectral selective perfect light absorption results in different optical colors corresponding to different thicknesses of silicon films. The device colors do not change when viewing from large angles with respect to the surface normal. Perfect absorption wavelength can be tuned over a wide wavelength range over 70 nm by thermal annealing. This new technology, which is low cost and compatible with silicon technology platform, paves the way for many applications such as optical color filters and wavelength selective photodetectors.

[1]  J. Aizenberg,et al.  Enhancement of absorption and color contrast in ultra-thin highly absorbing optical coatings , 2013 .

[2]  Robert L. Jarecki,et al.  Infrared plasmons on heavily-doped silicon , 2011 .

[3]  M. Lipson.  Guiding, modulating, and emitting light on Silicon-challenges and opportunities , 2005, Journal of Lightwave Technology.

[4]  Ricardo Ruiz,et al.  Self-assembly based plasmonic arrays tuned by atomic layer deposition for extreme visible light absorption. , 2013, Nano letters.

[5]  R. Magnusson,et al.  Effects of solid phase crystallization by rapid thermal annealing on the optical constants of sputtered amorphous silicon films , 2013 .

[6]  Federico Capasso,et al.  Nanometre optical coatings based on strong interference effects in highly absorbing media. , 2013, Nature materials.

[7]  R. Soref,et al.  Long-wave infrared tunable thin-film perfect absorber utilizing highly doped silicon-on-sapphire. , 2013, Optics express.

[8]  E. Almpanis,et al.  Designing photonic structures of nanosphere arrays on reflectors for total absorption , 2013 .

[9]  B. Jalali,et al.  Silicon Photonics , 2006, Journal of Lightwave Technology.

[10]  N. Zhang,et al.  Nanocavity Enhancement for Ultra‐Thin Film Optical Absorber , 2014, Advanced materials.

[11]  T. Chao,et al.  Ellipsometry measurement of the complex refractive index and thickness of polysilicon thin films , 1990 .

[12]  Jeremy B. Wright,et al.  Directional perfect absorption using deep subwavelength low-permittivity films , 2014, 1405.5569.

[13]  Hong‐Bo Sun,et al.  Anti-reflection resonance in distributed Bragg reflectors-based ultrathin highly absorbing dielectric and its application in solar cells , 2013 .

[14]  D. Wasserman,et al.  Strong absorption and selective emission from engineered metals with dielectric coatings. , 2013, Optics express.

[15]  Federico Capasso,et al.  Ultra-thin perfect absorber employing a tunable phase change material , 2012 .

[16]  A. Yariv.  Critical coupling and its control in optical waveguide-ring resonator systems , 2002, IEEE Photonics Technology Letters.

[17]  Reginald K. Lee,et al.  Ring fiber resonators based on fused-fiber grating add-drop filters:application to resonator coupling. , 2002, Optics letters.