The schematic diagram shows how up and down-conversion layers are applied to silicon solar cells. These layers are electronically isolated from the photovoltaic material, therefore do not experience the voltage matching problems associated with tandem solar cells.

Up and Down Conversion Layers Applied to a Silicon Solar Cell

The schematic diagram shows how up and down-conversion layers are applied to silicon solar cells. These layers are electronically isolated from the photovoltaic material, therefore do not experience the voltage matching problems associated with tandem solar cells. Please click on the image to expand.

Up and Down-conversion for Solar Cells

What is Up and Down-conversion for Solar Cells?

Up-conversion is the process by which two or more low energy (long wavelength) photons, which are transmitted by the photovoltaic cell, are converted into one high energy photon. The up converted photon has sufficient energy to bridge the solar cell band gap and can be absorbed. Down-conversion is the process by which one high energy photon, which is inefficiently absorbed by the photovoltaic cell due to thermalisation losses, is converted into two or more lower energy photons. These photons all have sufficient energy to be absorbed by the photovoltaic cell, with negligible thermalisation loss.

Up and down-conversion material is fabricated in layers which are independent of the photovoltaic cell. Therefore the optimised electrical properties of the cell are maintained. The up-conversion layer lies between the photovoltaic material and the back reflector, whereas the down-conversion layer lies on top of the photovoltaic material.

 

What are the challenges for Up and Down-conversion?

A significant challenge for up-conversion is that it is a non-linear optical process. This means that a very high intensity of incident light is required to produce only a small intensity of up-converted light. Furthermore, developing stable materials that exhibit high photon conversion efficiency is required.

The development of down conversion materials that exhibit the required energy conversion is the first challenge to be overcome. Once achieved, the down conversion layer will sit on top of the photovoltaic material: therefore the down-conversion layer must not interact with the light from the sun that is normally absorbed. A further challenge of down-conversion is to limit the loss of down-converted photons from the top surface of the layer.

 

How are these challenges being addressed by SISER researchers?

Heriot Watt University is carrying out research into the enhancement of up- and down-conversion layers for photovoltaic applications. Their work is based on the use of rare earth ions, which have been shown to be ideal candidates for the up-conversion process: they have luminescent properties that cover the required energy range (UV, visible and near-IR) and these properties are fairly invariant to the host material in which they are placed. Their current work is based on finding ways to control the propagation and interaction of light through these layers, to enhance the conversion. Heriot Watt University is working alongside the Fujian Institute of Research in the Structure of Matter, who are developing new luminescent materials for up and down-conversion.

 

SISER researchers with interest in this area are:

Full details of all SISER researchers are found on the SISER People Page

 

Publications

  1. Aruna Ivaturi, Sean K W MacDougall, Rosa Martin-Rodriguez, Marta Quintanilla, Jose Marques-Hueso, Karl W Kraemer, Andries Meijerink and Bryce S Richards. Optimizing infrared to near infrared upconversion quantum yield of beta-NaYF4:Er3+ in fluoropolymer matrix for photovoltaic devices. Journal of Applied Physics 114(1), 2013.
    BibTeX

    @article{Optimizing infrared to near infrared upconversion quantum yield of beta-NaYF4:Er3+ in fluoropolymer matrix for photovoltaic devices,
    	author = "Ivaturi, Aruna and MacDougall, Sean K. W. and Martin-Rodriguez, Rosa and Quintanilla, Marta and Marques-Hueso, Jose and Kraemer, Karl W. and Meijerink, Andries and Richards, Bryce S.",
    	title = "Optimizing infrared to near infrared upconversion quantum yield of beta-NaYF4:Er3+ in fluoropolymer matrix for photovoltaic devices",
    	journal = "Journal of Applied Physics",
    	volume = 114,
    	number = 1,
    	note = "Times Cited: 0 0",
    	year = 2013
    }
    
  2. Hang Lin, Jose Marques-Hueso, Daqin Chen, Yuansheng Wang and Bryce S Richards. Tm3+-sensitized up- and down-conversions in nano-structured oxyfluoride glass ceramics. Materials Research Bulletin 47(12):4433-4437, 2012.
    BibTeX

    @article{Tm3+-sensitized up- and down-conversions in nano-structured oxyfluoride glass ceramics,
    	author = "Lin, Hang and Marques-Hueso, Jose and Chen, Daqin and Wang, Yuansheng and Richards, Bryce S.",
    	title = "Tm3+-sensitized up- and down-conversions in nano-structured oxyfluoride glass ceramics",
    	journal = "Materials Research Bulletin",
    	volume = 47,
    	number = 12,
    	pages = "4433-4437",
    	note = "Times Cited: 1 Lin, Hang/F-6917-2013 1",
    	year = 2012
    }
    
  3. R Wehrspohn and A Gombert (eds.). Broadband excitation of upconversion in lanthanide doped fluorides for enhancement of Si solar cells. Proceedings of SPIE series, volume 8438, 2012.
    BibTeX

    @inbook{Broadband excitation of upconversion in lanthanide doped fluorides for enhancement of Si solar cells,
    	author = "MacDougall, Sean Kye Wallace and Aruna, Ivaturi and Marques-Hueso, Jose and Chen, Daqin and Wang, Yuansheng and Richards, Bryce S.",
    	title = "Broadband excitation of upconversion in lanthanide doped fluorides for enhancement of Si solar cells",
    	booktitle = "Photonics for Solar Energy Systems Iv",
    	editor = "Wehrspohn, R. and Gombert, A.",
    	series = "Proceedings of SPIE",
    	volume = 8438,
    	note = "Times Cited: 0 MacDougall, Sean/J-8617-2012 Conference on Photonics for Solar Energy Systems IV Apr 16-18, 2012 Brussels, BELGIUM SPIE; Brussels Photon Team (B-PHOT); Brussels-Capital Reg; Fonds Wetenschappelijk Onderzoek (FWO); Int Commiss Opt (ICO); Ville Bruxelles",
    	year = 2012
    }
    
  4. Sean K W MacDougall, Ivaturi Aruna, Jose Marques-Hueso, Karl W Kraemer and Bryce S Richards. Ultra-high photoluminescent quantum yield of beta-NaYF4: 10% Er3+ via broadband excitation of upconversion for photovoltaic devices. Optics Express 20(23):A879-A887, 2012.
    BibTeX

    @article{Ultra-high photoluminescent quantum yield of beta-NaYF4: 10% Er3+ via broadband excitation of upconversion for photovoltaic devices,
    	author = "MacDougall, Sean K. W. and Aruna, Ivaturi and Marques-Hueso, Jose and Kraemer, Karl W. and Richards, Bryce S.",
    	title = "Ultra-high photoluminescent quantum yield of beta-NaYF4: 10% Er3+ via broadband excitation of upconversion for photovoltaic devices",
    	journal = "Optics Express",
    	volume = 20,
    	number = 23,
    	pages = "A879-A887",
    	note = "Times Cited: 4 4",
    	year = 2012
    }
    
  5. L Tsakalakos (ed.). Advances in Spectral Conversion for Photovoltaics: Up-converting Er3+ Doped YF3 Nano-crystals in Transparent Glass Ceramic. Proceedings of SPIE series, volume 8111, 2011.
    BibTeX

    @inbook{Advances in Spectral Conversion for Photovoltaics: Up-converting Er3+ Doped YF3 Nano-crystals in Transparent Glass Ceramic,
    	author = "Marques-Hueso, Jose and Chen, Daqin and MacDougall, Sean K. W. and Wang, Yuansheng and Richards, Bryce S.",
    	title = "Advances in Spectral Conversion for Photovoltaics: Up-converting Er3+ Doped YF3 Nano-crystals in Transparent Glass Ceramic",
    	booktitle = "Next Generation",
    	editor = "Tsakalakos, L.",
    	series = "Proceedings of SPIE",
    	volume = 8111,
    	note = "Times Cited: 0 MacDougall, Sean/J-8617-2012 Nano Conference on Next Generation (Nano) Photonic and Cell Technologies for Solar Energy Conversion II Aug 21-23, 2011 San Diego, CA Spie",
    	year = 2011
    }
    
  6. Rosa Martin-Rodriguez, Stefan Fischer, Aruna Ivaturi, Benjamin Froehlich, Karl W Kraemer, Jan C Goldschmidt, Bryce S Richards and Andries Meijerink. Highly Efficient IR to NIR Upconversion in Gd2O2S: Er3+ for Photovoltaic Applications. Chemistry of Materials 25(9):1912-1921, 2013.
    BibTeX

    @article{Highly Efficient IR to NIR Upconversion in Gd2O2S: Er3+ for Photovoltaic Applications,
    	author = "Martin-Rodriguez, Rosa and Fischer, Stefan and Ivaturi, Aruna and Froehlich, Benjamin and Kraemer, Karl W. and Goldschmidt, Jan C. and Richards, Bryce S. and Meijerink, Andries",
    	title = "Highly Efficient IR to NIR Upconversion in Gd2O2S: Er3+ for Photovoltaic Applications",
    	journal = "Chemistry of Materials",
    	volume = 25,
    	number = 9,
    	pages = "1912-1921",
    	note = "Times Cited: 0 Goldschmidt, Jan Christoph/C-1807-2008 Goldschmidt, Jan Christoph/0000-0003-3256-1366 0",
    	year = 2013
    }
    
  7. Paolo Pizzol, Jose Marques-Hueso, Neil Robertson, Isidora Freris, Luca Bellotto, Thomas J J Meyer and Bryce S Richards. Optical properties of lanthanide dyes for spectral conversion encapsulated in porous silica nanoparticles. In Conference on Photonics for Solar Energy Systems IV 8438. 2012.
    BibTeX

    @inproceedings{Optical properties of lanthanide dyes for spectral conversion encapsulated in porous silica nanoparticles,
    	author = "Pizzol, Paolo and Marques-Hueso, Jose and Robertson, Neil and Freris, Isidora and Bellotto, Luca and Meyer, Thomas J. J. and Richards, Bryce S.",
    	title = "Optical properties of lanthanide dyes for spectral conversion encapsulated in porous silica nanoparticles",
    	booktitle = "Conference on Photonics for Solar Energy Systems IV",
    	series = "Proceedings of SPIE",
    	volume = 8438,
    	note = "Times Cited: 0",
    	year = 2012
    }
    
  8. B S Richards. Enhancing the performance of silicon solar cells via the application of passive luminescence conversion layers. Solar Energy Materials and Solar Cells 90(15):2329-2337, 2006.
    BibTeX

    @article{Enhancing the performance of silicon solar cells via the application of passive luminescence conversion layers,
    	author = "Richards, B. S.",
    	title = "Enhancing the performance of silicon solar cells via the application of passive luminescence conversion layers",
    	journal = "Solar Energy Materials and Solar Cells",
    	volume = 90,
    	number = 15,
    	pages = "2329-2337",
    	note = "Times Cited: 114 Si Symposium on Solar Cells and Solar Energy Materials held at the International Materials Research Congress (IMRC 2005) Aug 22-25, 2005 Cancun, MEXICO 122",
    	year = 2006
    }
    
  9. B S Richards. Luminescent layers for enhanced silicon solar cell performance: Down-conversion. Solar Energy Materials and Solar Cells 90(9):1189-1207, 2006.
    BibTeX

    @article{Luminescent layers for enhanced silicon solar cell performance: Down-conversion,
    	author = "Richards, B. S.",
    	title = "Luminescent layers for enhanced silicon solar cell performance: Down-conversion",
    	journal = "Solar Energy Materials and Solar Cells",
    	volume = 90,
    	number = 9,
    	pages = "1189-1207",
    	note = "Times Cited: 177 184",
    	year = 2006
    }
    
  10. R Wehrspohn and A Gombert (eds.). Up- and Down-Conversion Materials for Photovoltaic Devices. Proceedings of SPIE series, volume 8438, 2012.
    BibTeX

    @inbook{Up- and Down-Conversion Materials for Photovoltaic Devices,
    	author = "Richards, Bryce S. and Aruna, Ivaturi and MacDougall, Sean K. W. and Marques-Hueso, Jose",
    	title = "Up- and Down-Conversion Materials for Photovoltaic Devices",
    	booktitle = "Photonics for Solar Energy Systems Iv",
    	editor = "Wehrspohn, R. and Gombert, A.",
    	series = "Proceedings of SPIE",
    	volume = 8438,
    	note = "Times Cited: 0 MacDougall, Sean/J-8617-2012 Conference on Photonics for Solar Energy Systems IV Apr 16-18, 2012 Brussels, BELGIUM SPIE; Brussels Photon Team (B-PHOT); Brussels-Capital Reg; Fonds Wetenschappelijk Onderzoek (FWO); Int Commiss Opt (ICO); Ville Bruxelles",
    	year = 2012
    }
    
  11. B S Richards and A Shalav. The role of polymers in the luminescence conversion of sunlight for enhanced solar cell performance. Synthetic Metals 154(1-3):61-64, 2005.
    BibTeX

    @article{The role of polymers in the luminescence conversion of sunlight for enhanced solar cell performance,
    	author = "Richards, B. S. and Shalav, A.",
    	title = "The role of polymers in the luminescence conversion of sunlight for enhanced solar cell performance",
    	journal = "Synthetic Metals",
    	volume = 154,
    	number = "1-3",
    	pages = "61-64",
    	note = "Times Cited: 31 Shalav, Avi/E-3247-2010 Si International Conference on Science and Technology of Synthetic Metals Jun 28-jul 02, 2004 Wollongong, AUSTRALIA 32",
    	year = 2005
    }
    
  12. Bryce S Richards and Avi Shalav. Enhancing the near-infrared spectral response of silicon optoelectronic devices via up-conversion. Ieee Transactions on Electron Devices 54(10):2679-2684, 2007.
    BibTeX

    @article{Enhancing the near-infrared spectral response of silicon optoelectronic devices via up-conversion,
    	author = "Richards, Bryce S. and Shalav, Avi",
    	title = "Enhancing the near-infrared spectral response of silicon optoelectronic devices via up-conversion",
    	journal = "Ieee Transactions on Electron Devices",
    	volume = 54,
    	number = 10,
    	pages = "2679-2684",
    	note = "Times Cited: 49 Shalav, Avi/E-3247-2010 50",
    	year = 2007
    }
    
  13. A Shalav, B S Richards and M A Green. Luminescent layers for enhanced silicon solar cell performance: Up-conversion. Solar Energy Materials and Solar Cells 91(9):829-842, 2007.
    BibTeX

    @article{Luminescent layers for enhanced silicon solar cell performance: Up-conversion,
    	author = "Shalav, A. and Richards, B. S. and Green, M. A.",
    	title = "Luminescent layers for enhanced silicon solar cell performance: Up-conversion",
    	journal = "Solar Energy Materials and Solar Cells",
    	volume = 91,
    	number = 9,
    	pages = "829-842",
    	note = "Times Cited: 140 Shalav, Avi/E-3247-2010 146",
    	year = 2007
    }
    
  14. A Shalav, B S Richards, K Kramer, H Gudel and Ieee. Improvements of an up-conversion NaYF4 : Er3+ phosphor/silicon solar cell system for an enhanced response in the near-infrared. Ieee Photovoltaic Specialists Conference series, pages 114-117, 2005.
    BibTeX

    @inbook{Improvements of an up-conversion NaYF4 : Er3+ phosphor/silicon solar cell system for an enhanced response in the near-infrared,
    	author = "Shalav, A. and Richards, B. S. and Kramer, K. and Gudel, H. and Ieee",
    	title = "Improvements of an up-conversion NaYF4 : Er3+ phosphor/silicon solar cell system for an enhanced response in the near-infrared",
    	booktitle = "Conference Record of the Thirty-First IEEE Photovoltaic Specialists Conference - 2005",
    	series = "Ieee Photovoltaic Specialists Conference",
    	pages = "114-117",
    	note = "Times Cited: 1 Shalav, Avi/E-3247-2010 31st IEEE Photovoltaic Specialists Conference Jan 03-07, 2005 Lake Buena Vista, FL IEEE Electron Devices Soc; IEEE",
    	year = 2005
    }
    
  15. A Shalav, B S Richards, T Trupke, R P Corkish, K W Kramer, H U Gudel and M A Green. The application of up-converting phosphors for increased solar cell conversion efficiencies. Proceedings of 3rd World Conference on Photovoltaic Energy Conversion, Vols a-C series, 2003.
    BibTeX

    @book{The application of up-converting phosphors for increased solar cell conversion efficiencies,
    	author = "Shalav, A. and Richards, B. S. and Trupke, T. and Corkish, R. P. and Kramer, K. W. and Gudel, H. U. and Green, M. A.",
    	title = "The application of up-converting phosphors for increased solar cell conversion efficiencies",
    	series = "Proceedings of 3rd World Conference on Photovoltaic Energy Conversion, Vols a-C",
    	note = "Times Cited: 1 Shalav, Avi/E-3247-2010 3rd World Conference on Photovoltaic Energy Conversion May 11-18, 2003 Osaka, JAPAN WCPEC-3 Org Comm; Inst Elect, Informat & Commun Engineers; Japan Soc Aeronaut & Space Sci; Chem Soc Japan; Japan Sect Int Solar Energy Soc; Electrochem Soc Japan; Japan Solar Energy Soc",
    	pages = "248-250",
    	year = 2003
    }
    
  16. A Shalav, B S Richards, T Trupke, K W Kramer and H U Gudel. Application of NaYF4 : Er3+ up-converting phosphors for enhanced near-infrared silicon solar cell response. Applied Physics Letters 86(1), 2005.
    BibTeX

    @article{Application of NaYF4 : Er3+ up-converting phosphors for enhanced near-infrared silicon solar cell response,
    	author = "Shalav, A. and Richards, B. S. and Trupke, T. and Kramer, K. W. and Gudel, H. U.",
    	title = "Application of NaYF4 : Er3+ up-converting phosphors for enhanced near-infrared silicon solar cell response",
    	journal = "Applied Physics Letters",
    	volume = 86,
    	number = 1,
    	note = "Times Cited: 212 Shalav, Avi/E-3247-2010 219",
    	year = 2005
    }
    
  17. T Trupke, A Shalav, B S Richards, P Wuerfel and M A Green. Efficiency enhancement of solar cells by luminescent up-conversion of sunlight. Solar Energy Materials and Solar Cells 90(18-19):3327-3338, 2006.
    BibTeX

    @article{Efficiency enhancement of solar cells by luminescent up-conversion of sunlight,
    	author = "Trupke, T. and Shalav, A. and Richards, B. S. and Wuerfel, P. and Green, M. A.",
    	title = "Efficiency enhancement of solar cells by luminescent up-conversion of sunlight",
    	journal = "Solar Energy Materials and Solar Cells",
    	volume = 90,
    	number = "18-19",
    	pages = "3327-3338",
    	note = "Times Cited: 82 Shalav, Avi/E-3247-2010 14th International Photovoltaic Science and Engineering Conference Jan 27-feb 01, 2004 Bangkok, THAILAND 86",
    	year = 2006
    }