Stencil-Nanopatterned Back Reflectors for Thin-Film Amorphous Silicon n-i-p Solar Cells

We fabricated amorphous silicon n-i-p solar cells with two types of nanopatterned back reflectors using stencil lithography. One reflector type has a plasmonic grating that is embedded in the ZnO layer; the other one has a metallic grating patterned on top of the Ag layer. From comparing the short-circuit current densities of the two device types, we conclude that light trapping through grating coupling is more efficient than coupling of light through the excitation of localized surface plasmons. The back reflectors were patterned with dot arrays by evaporation of Ag through millimeter-size stencil membranes. The stencils themselves were patterned by wafer-scale nanosphere lithography. The dot arrays have a periodicity of 428 nm and efficiently scatter light in the near-infrared wavelength range. Both back reflectors types lead to the same morphology for the silicon films. This allows us a fair comparison of the two light coupling mechanisms. We found a 14% and 19% short-circuit current density enhancement for the plasmonic and for the metallic grating, respectively. The external quantum efficiency gains between 550 and 650 nm show similar guided modes resonances for both device types, but the excitation is stronger for the device with the metallic grating.

[1]  Christophe Ballif,et al.  Photocurrent increase in n-i-p thin film silicon solar cells by guided mode excitation via grating coupler , 2010 .

[2]  M. Green,et al.  Surface plasmon enhanced silicon solar cells , 2007 .

[3]  Huang,et al.  Optical and electrical properties of thin silver films grown under ion bombardment. , 1986, Physical review. B, Condensed matter.

[4]  J. Brugger,et al.  SiN membranes with submicrometer hole arrays patterned by wafer-scale nanosphere lithography , 2011 .

[5]  Yi Cui,et al.  Effects of nanostructured back reflectors on the external quantum efficiency in thin film solar cells , 2011 .

[6]  Yi Cui,et al.  High‐Efficiency Amorphous Silicon Solar Cell on a Periodic Nanocone Back Reflector , 2012 .

[7]  Hiroshi Sakai,et al.  Effects of Surface Morphology of Transparent Electrode on the Open-Circuit Voltage in a-Si:H Solar Cells , 1990 .

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

[9]  B. Rech,et al.  Texture etched ZnO:Al coated glass substrates for silicon based thin film solar cells , 1999 .

[10]  Renrong Liang,et al.  Application of plasmonic silver island films in thin-film silicon solar cells , 2012 .

[11]  Michael J. Burns,et al.  Efficient nanocoax‐based solar cells , 2010 .

[12]  P. Luo,et al.  Improved light absorption in thin-film silicon solar cells by integration of silver nanoparticles , 2008 .

[13]  G. Whitesides,et al.  Light Trapping in Ultrathin Plasmonic Solar Cells References and Links , 2022 .

[14]  Takumi Sannomiya,et al.  Metallic nanodot arrays by stencil lithography for plasmonic biosensing applications. , 2011, ACS nano.

[15]  V. Terrazzoni-Daudrix,et al.  Optimization of amorphous silicon thin film solar cells for flexible photovoltaics , 2008 .

[16]  Helmut Stiebig,et al.  Thin-film silicon solar cells with efficient periodic light trapping texture , 2007 .

[17]  S. Guha,et al.  Progress in amorphous and nanocrystalline silicon solar cells , 2006 .

[18]  H. Atwater,et al.  Plasmonics for improved photovoltaic devices. , 2010, Nature materials.

[19]  Yi Cui,et al.  Light trapping in solar cells: can periodic beat random? , 2012, ACS nano.

[20]  C. Ballif,et al.  Photocurrent enhancement in thin film amorphous silicon solar cells with silver nanoparticles , 2011 .

[21]  Y. Akimov,et al.  Enhancement of optical absorption in thin-film solar cells through the excitation of higher-order nanoparticle plasmon modes. , 2009, Optics express.

[22]  C. Ballif,et al.  Electrically flat/optically rough substrates for efficiencies above 10% in n-i-p thin-film silicon solar cells , 2012 .

[23]  J. Brugger,et al.  Metallic nanowires by full wafer stencil lithography. , 2008, Nano letters.

[24]  H. Fujiwara,et al.  Enhancement of light trapping in thin-film hydrogenated microcrystalline Si solar cells using back reflectors with self-ordered dimple pattern , 2008 .

[25]  C. Ballif,et al.  Window layer with p doped silicon oxide for high Voc thin-film silicon n-i-p solar cells , 2011 .

[26]  Zongfu Yu,et al.  Nanodome solar cells with efficient light management and self-cleaning. , 2010, Nano letters.

[27]  Gold membranes with large arrays of sub-μm holes fabricated by wafer-scale Nanosphere Lithography , 2011, 2011 16th International Solid-State Sensors, Actuators and Microsystems Conference.

[28]  M. Stutzmann,et al.  Periodic light coupler gratings in amorphous thin film solar cells , 2001 .

[29]  Christophe Ballif,et al.  UV‐nano‐imprint lithography technique for the replication of back reflectors for n‐i‐p thin film silicon solar cells , 2011 .

[30]  Light Trapping by Ag Nanoparticles Chemically Assembled inside Thin-Film Hydrogenated Microcrystalline Si Solar Cells , 2012 .

[31]  K. Catchpole,et al.  Absorption enhancement due to scattering by dipoles into silicon waveguides , 2006 .

[32]  C. Ballif,et al.  Polycrystalline ZnO: B grown by LPCVD as TCO for thin film silicon solar cells , 2010 .

[33]  S. Maier,et al.  Plasmonics: Localization and guiding of electromagnetic energy in metal/dielectric structures , 2005 .

[34]  H. Atwater,et al.  Modeling light trapping in nanostructured solar cells. , 2011, ACS Nano.

[35]  Ali Naqavi,et al.  Resonances and absorption enhancement in thin film silicon solar cells with periodic interface texture , 2011 .

[36]  Miro Zeman,et al.  Diffraction Gratings for Light Trapping in Thin-Film Silicon Solar Cells , 2008 .

[37]  E. Yablonovitch.  Statistical ray optics , 1982 .