Broadband antireflective nano-cones for tandem solar cells.

Broadband solar cell antireflection coatings made of nano-cones are studied in square lattices of ZnS, TiO(2) and Si(3)N(4). In the best case, the spectrally integrated transmittance (accounting for both reflection and dielectric absorption losses) for direct solar radiation is 99 %, which represents a four-fold decrease in transmission losses in comparison to a standard antireflective coating bilayer. The dependence of the transmission as a function of nanostructure dimensions is studied, showing a wide maximum, thus leading to a high tolerance for manufacturing errors. This high transmittance is also robust against deviations from normal incidence. Our analysis suggests that the high transmittance is due not only to an effective gradual index effect, but is also due to light coupling to quasiguided modes in the photonic crystal leaking mostly towards the substrate.

[1]  S. Giordano,et al.  Effective medium theory for dispersions of dielectric ellipsoids , 2003 .

[2]  S. Denbaars,et al.  Surface structured optical coatings with near-perfect broadband and wide-angle antireflective properties. , 2014, Nano letters.

[3]  Lucio Claudio Andreani,et al.  Photonic light-trapping versus Lambertian limits in thin film silicon solar cells with 1D and 2D periodic patterns. , 2012, Optics express.

[4]  E. Fred Schubert,et al.  Optical thin-film materials with low refractive index for broadband elimination of Fresnel reflection , 2007 .

[5]  V. Polojärvi,et al.  Moth-Eye Antireflection Coatings Fabricated by Nanoimprint Lithography on Dilute Nitride Solar Cell , 2011 .

[6]  Drew A. Pommet,et al.  Optimal design for antireflective tapered two-dimensional subwavelength grating structures , 1995 .

[7]  Marta Victoria,et al.  Antireflective coatings for multijunction solar cells under wide-angle ray bundles. , 2012, Optics express.

[8]  Dong-Sing Wuu,et al.  Tri-layer antireflection coatings (SiO2/SiO2–TiO2/TiO2) for silicon solar cells using a sol–gel technique , 2006 .

[9]  W. Price.  Global optimization by controlled random search , 1983 .

[10]  T. Ishihara,et al.  Quasiguided modes and optical properties of photonic crystal slabs , 2002 .

[11]  Shanhui Fan,et al.  Analysis of guided resonances in photonic crystal slabs , 2002 .

[12]  V. Polojärvi,et al.  Nanostructured broadband antireflection coatings on AlInP fabricated by nanoimprint lithography , 2010 .

[13]  Won-Kyu Park,et al.  Efficiency improvement of III–V GaAs solar cells using biomimetic TiO2 subwavelength structures with wide-angle and broadband antireflection properties , 2014 .

[14]  L. Miao,et al.  Optical properties of polycrystalline and epitaxial anatase and rutile TiO2 thin films by rf magnetron sputtering , 2003 .

[15]  M. L. Dotor,et al.  Optical absorption enhancement in a hybrid system photonic crystal - thin substrate for photovoltaic applications. , 2012, Optics express.

[16]  John E Bowers,et al.  Design of antireflective nanostructures and optical coatings for next-generation multijunction photovoltaic devices. , 2014, Optics express.

[17]  Antonio Luque,et al.  Handbook of photovoltaic science and engineering , 2011 .

[18]  A. Luque,et al.  Upper limits to absorption enhancement in thick solar cells using diffraction gratings , 2011 .

[19]  Andrea Alù,et al.  Comparing plasmonic and dielectric gratings for absorption enhancement in thin-film organic solar cells. , 2012, Optics express.

[20]  Hiroshi Nakanishi,et al.  Optical Properties of (AlxGa1-x)0.5In0.5P Quaternary Alloys , 1994 .

[21]  P. Yu,et al.  Compound biomimetic structures for efficiency enhancement of Ga₀.₅In₀.₅P/GaAs/Ge triple-junction solar cells. , 2014, Optics express.

[22]  Shanhui Fan,et al.  S4 : A free electromagnetic solver for layered periodic structures , 2012, Comput. Phys. Commun..

[23]  Daniel J. Friedman,et al.  High‐Efficiency III‐V Multijunction Solar Cells , 2011 .

[24]  C. Algora,et al.  Modelling of GaAs solar cells under wide angle cones of homogeneous light , 1999 .

[25]  Zongfu Yu,et al.  Fundamental Limit of Nanophotonic Light-trapping in Solar Cells , 2010 .

[26]  Eric Guiot,et al.  Wafer bonded four‐junction GaInP/GaAs//GaInAsP/GaInAs concentrator solar cells with 44.7% efficiency , 2014 .

[27]  M. Green,et al.  19.8% efficient “honeycomb” textured multicrystalline and 24.4% monocrystalline silicon solar cells , 1998 .

[28]  V. Polojärvi,et al.  Moth‐eye antireflection coating fabricated by nanoimprint lithography on 1 eV dilute nitride solar cell , 2012 .

[29]  E. Palik.  Handbook of Optical Constants of Solids , 1997 .

[30]  W. Pardee,et al.  Optical Properties of an Ionic Crystal Slab , 1966 .

[31]  A. Polman,et al.  Designing dielectric resonators on substrates: combining magnetic and electric resonances. , 2013, Optics express.

[32]  M. Lončar,et al.  Optimal broadband antireflective taper. , 2013, Optics letters.

[33]  H. R. Philipp,et al.  Silicon Nitride (Si3N4) (Noncrystalline) , 1997 .

[34]  M. L. Dotor,et al.  Photon management with nanostructures on concentrator solar cells , 2013 .

[35]  Stuart A. Boden,et al.  Optimization of moth‐eye antireflection schemes for silicon solar cells , 2010 .