UV‐nano‐imprint lithography technique for the replication of back reflectors for n‐i‐p thin film silicon solar cells

Texturing of interfaces in thin film silicon solar cells is essential to enhance the produced photocurrent and thus the efficiencies.AUVnano-imprint-lithography (UV-NIL) replication processwas developed to prepare substrates with textures that are suitable for the growth of n-i-p thin film silicon solar cells. Morphological and optical analyses were performed to assess the quality of the replicas. A comparison of single junction amorphous solar cells on the original structures and on their replicas on glass revealed good light trapping and excellent electrical properties on the replicated structures. A tandem amorphous silicon/amorphous silicon (a-Si/a-Si) cell deposited on a replica on plastic exhibits a stabilized efficiency of 8.1% and a high yield of 90% of good cells in laboratory conditions. It demonstrates the possibility to obtain appropriate structure on low cost plastic substrate. Copyright © 2010 John Wiley & Sons, Ltd.

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

[2]  J. Andreu,et al.  Hot Embossing of Polymer Substrates for Thin Silicon Cell Applications , 2006, 2006 IEEE 4th World Conference on Photovoltaic Energy Conference.

[3]  Hiroshi Sakai,et al.  Production technology for amorphous silicon-based flexible solar cells , 2001 .

[4]  Bernd Stannowski,et al.  Helianthos : Roll-to-Roll deposition of flexible solar cell modules , 2007 .

[5]  Michio Kondo,et al.  Effect of self-orderly textured back reflectors on light trapping in thin-film microcrystalline silicon solar cells , 2009 .

[6]  Maurits C. R. Heijna,et al.  Embossing of light trapping patterns in sol-gel coatings for thin film silicon solar cells , 2008, Optics + Photonics for Sustainable Energy.

[7]  J. Gómez‐Herrero,et al.  WSXM: a software for scanning probe microscopy and a tool for nanotechnology. , 2007, The Review of scientific instruments.

[8]  A. Shah,et al.  Characterisation of rough reflecting substrates incorporated into thin‐film silicon solar cells , 2006 .

[9]  M. Zeman,et al.  Optical modeling of a-Si:H solar cells deposited on textured glass/SnO2 substrates , 2002 .

[10]  Arvind Shah,et al.  Low pressure chemical vapour deposition of ZnO layers for thin-film solar cells: temperature-induced morphological changes , 2005 .

[11]  Christophe Ballif,et al.  TCOs for nip thin film silicon solar cells , 2009 .

[12]  C. Ballif,et al.  Influence of the ZnO buffer on the guided mode structure in Si/ZnO/Ag multilayers , 2009 .

[13]  Christophe Ballif,et al.  Opto-electronic properties of rough LP-CVD ZnO:B for use as TCO in thin-film silicon solar cells , 2007 .

[14]  S. Guha,et al.  Study of back reflectors for amorphous silicon alloy solar cell application , 1991 .

[15]  Y. Hayashi,et al.  Efficiency of the a-Si:H solar cell and grain size of SnO2transparent conductive film , 1983, IEEE Electron Device Letters.

[16]  H. Davies.  The reflection of electromagnetic waves from a rough surface , 1954 .

[17]  H. Atwater,et al.  Improved red-response in thin film a-Si:H solar cells with soft-imprinted plasmonic back reflectors , 2009 .

[18]  Y. Marfaing.  Evaluation of multijunction structures using amorphous Si-Ge alloys , 1979 .

[19]  Volker Wittwer,et al.  Diffraction gratings and buried nano-electrodes—architectures for organic solar cells , 2004 .

[20]  L. Guo,et al.  High‐Speed Roll‐to‐Roll Nanoimprint Lithography on Flexible Plastic Substrates , 2008 .

[21]  C. Ballif,et al.  Plasmonic absorption in textured silver back reflectors of thin film solar cells , 2008 .

[22]  Arvind Shah,et al.  Relation between substrate surface morphology and microcrystalline silicon solar cell performance , 2008 .

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

[24]  C. Ballif,et al.  N/I buffer layer for substrate microcrystalline thin film silicon solar cell , 2008 .