Zeroth order Fabry-Perot resonance enabled ultra-thin perfect light absorber using percolation aluminum and silicon nanofilms

We demonstrated perfect light absorption in optical nanocavities made of ultra-thin percolation aluminum and silicon films deposited on an aluminum surface. The total layer thickness of the aluminum and silicon films is one order of magnitude less than perfect absorption wavelength in the visible spectral range. The ratio of silicon cavity layer thickness to perfect absorption wavelength decreases as wavelength decreases due to the increased phase delays at silicon-aluminum boundaries at shorter wavelengths. It is explained that perfect light absorption is due to critical coupling of incident wave to the fundamental Fabry-Perot resonance mode of the structure where the round trip phase delay is zero. Simulations were performed and the results agree well with the measurement results. ©2016 Optical Society of America OCIS codes: (310.0310) Thin films; (310.3915) Metallic, opaque, and absorbing coatings; (160.4236) Nanomaterials. References and links 1. K. X. Wang, Z. Yu, V. Liu, Y. Cui, and S. Fan, “Absorption enhancement in ultrathin crystalline silicon solar cells with antireflection and light-trapping nanocone gratings,” Nano Lett. 12(3), 1616–1619 (2012). 2. J. Leuthold, C. Koos, and W. Freude, “Nonlinear silicon photonics,” Nat. Photonics 4(8), 535–544 (2010). 3. J. N. Anker, W. P. Hall, O. Lyandres, N. C. Shah, J. Zhao, and R. P. Van Duyne, “Biosensing with plasmonic nanosensors,” Nat. Mater. 7(6), 442–453 (2008). 4. M. G. Nielsen, A. Pors, O. Albrektsen, and S. I. Bozhevolnyi, “Efficient absorption of visible radiation by gap plasmon resonators,” Opt. Express 20(12), 13311–13319 (2012). 5. J. Hendrickson, J. Guo, B. Zhang, W. Buchwald, and R. Soref, “Wideband perfect light absorber at midwave infrared using multiplexed metal structures,” Opt. Lett. 37(3), 371–373 (2012). 6. Z. Fang, Y. R. Zhen, L. Fan, X. Zhu, and P. Nordlander, “Tunable wide-angle plasmonic perfect absorber at visible frequencies,” Phys. Rev. B 85(24), 245401 (2012). 7. B. Zhang, J. Hendrickson, and J. Guo, “Multispectral near perfect metamaterial absorbers using spatially multiplexed plasmon resonance metal square structures,” J. Opt. Soc. Am. B 30(3), 656–662 (2013). 8. T. Sun, C. F. Guo, F. Cao, E. M. Akinoglu, Y. Wang, M. Giersig, Z. Ren, and K. Kempa, “A broadband solar absorber with 12 nm thick ultrathin a-Si layer by using random metallic nanomeshes,” Appl. Phys. Lett. 104(25),