High-performance solar cells with lower cost

Chinese researchers have developed solar cells which are high efficiency and lower cost.

Nano Energy Journal – Modulation-doped ZnO as high performance electron-selective layer for efficient silicon heterojunction solar cells

Highlights

• The Li-doped ZnO (Li-ZnO) layer was fabricated by a simple, mild and efficient solution process, and the work function was tuned precisely in a relative large range (from 4.15 to 3.85 eV).
• The contact resistivity (ρc) was dramatically decreased from 100 mΩ cm2 to 18 mΩ·cm2 for n-Si/Li-ZnO/Al structure with optimized Li concentration.
• Remarkable efficiency of 15.1% and open-circuit voltage of 643 mV, for the solution-proceeded PEDOT: PSS/Si heterojunction solar cell, was achieved.

It has been a long-time dream for photovoltaic (PV) researchers to achieve high-performance silicon (Si) heterojunction solar cells (SCs) relying only on low-temperature and solution-based processes. A newly emerging PV technique of carrier-selective contacts, which comprise high-performance hole- and electron-selective layers (HSL and ESL) for both polarities on Si substrate, is highly expected to meet this dream. Here, we report a precise control of the doping level in solution-processed ZnO thin films and their successful application as ESLs for organic/Si heterojunction SCs. We show that addition of Li in ZnO (Li-ZnO) allows for the accurate tuning of its work function from 4.15 to 3.85 eV. In case of Si/ZnO/Al heterocontact, presence of the Li-ZnO layer with optimized Li concentration results in a remarkable enhancement in extraction of electrons, showing by a big reduction of contact resistivity (ρc) from 100 to 18 mΩ cm2. When used in combination with an interfacial passivation layer of intrinsic amorphous silicon (a-Si:H), the bilayer ESL of a-Si:H/Li-ZnO helps to yield an open-circuit voltage (Voc) of 643 mV and an efficiency up to 15.1%, both remarkable for an organic/Si SC fabricated using solution-based processes. Progress in tuning the Li-ZnO properties to yield improved interfaces between Si and rear-sided electrode may open up a new direction of exploring more functional materials for high performance ESLs via effectively solution-based method.

21 thoughts on “High-performance solar cells with lower cost”

  1. ‘Oct 23, 2018. Glenorchy Air has suspended its operations out of respect for its founder who died yesterday. The airline said in a statement that Queenstown aviation pioneer Robert Rutherford died last night, after a fall while undertaking property maintenance.’ At 71, he had survived countless flights across the rugged Southern Alps, but died cleaning the solar panels on his roof.

    Reply
  2. There are other issues with solar PV that are not being addressed. First, no one has yet developed a replacement for ITO for the transparent upper electrode. Solar PV will NEVER scale up cost effectively until such a material is developed. Second, material life time. Does this material have a long lifetime? What about oxidation? If oxidation is a problem (as with the conductive polymers – Plextronics – if they’re still around), then the solar cells have to be hermetically sealed from the atmosphere.I will give this credit for the fact it uses Zinc. Zinc is good because Indium is produced as a byproduct of Zinc refining. So, both materials come from the same source. However, this still does not resolve the first problem. Zinc is also non-toxic, unlike for example Cadmium-Tellurium solar cells that are not even allowed in Japan due to the toxicity issue.

    Reply
  3. I will admit lack of knowledge on solar cell technology. So I fail to see why this is such a breakthrough unless they are able to increase the efficiency of the cell well above 22% the current level of efficiency of cells being mass produced. The cost of installing a typical solar cell system on a house is driven by soft costs and installation cost not the cell costs. SOO installing the most efficient cells if the cost is reasonable makes more sense.

    Reply
  4. What is needed is something that you can add to asphalt shingles at a small cost while not affecting the installation of the shingles much. This way every roof is a solar roof or has the potential. Lusk solar roof tiles are interesting but still too expensive. Maybe their prices will drop over the upcoming years.

    Reply
  5. I don’t think solar is good for anything besides thermal collection in the near future. If only they’d put effort in cheap thermal batteries and a hot water system to both store heat for winter heating and provide warm water.

    Reply
  6. I don’t think solar is good for anything besides thermal collection in the near future. If only they’d put effort in cheap thermal batteries and a hot water system to both store heat for winter heating and provide warm water.

    Reply
  7. Can’t they just rotate the whole thing 90 degrees. The sun coming from the “side” of electrode/active layers stacked ontop each other.

    Reply
  8. I don’t think solar is good for anything besides thermal collection in the near future. If only they’d put effort in cheap thermal batteries and a hot water system to both store heat for winter heating and provide warm water.

    Reply
  9. Relatively long life. What you get is slow deterioration over time. It won’t last forever because nothing does. Your roof will need to eventually be re-shingled.

    Reply
  10. What is needed is something that you can add to asphalt shingles at a small cost while not affecting the installation of the shingles much. This way every roof is a solar roof or has the potential. Lusk solar roof tiles are interesting but still too expensive. Maybe their prices will drop over the upcoming years.

    Reply
  11. It’s best to pay somebody else younger to do this task. Note, typically the cleaner is just sprayed on and then later washed off so you actually don’t need to get on the roof, just up to roof level.

    Reply
  12. There are other issues with solar PV that are not being addressed. First, no one has yet developed a replacement for ITO for the transparent upper electrode. Solar PV will NEVER scale up cost effectively until such a material is developed. Second, material life time. Does this material have a long lifetime? What about oxidation? If oxidation is a problem (as with the conductive polymers – Plextronics – if they’re still around), then the solar cells have to be hermetically sealed from the atmosphere.I will give this credit for the fact it uses Zinc. Zinc is good because Indium is produced as a byproduct of Zinc refining. So, both materials come from the same source. However, this still does not resolve the first problem. Zinc is also non-toxic, unlike for example Cadmium-Tellurium solar cells that are not even allowed in Japan due to the toxicity issue.

    Reply
  13. I will admit lack of knowledge on solar cell technology. So I fail to see why this is such a breakthrough unless they are able to increase the efficiency of the cell well above 22% the current level of efficiency of cells being mass produced. The cost of installing a typical solar cell system on a house is driven by soft costs and installation cost not the cell costs. SOO installing the most efficient cells if the cost is reasonable makes more sense.

    Reply
  14. What is needed is something that you can add to asphalt shingles at a small cost while not affecting the installation of the shingles much. This way every roof is a solar roof or has the potential.

    Lusk solar roof tiles are interesting but still too expensive. Maybe their prices will drop over the upcoming years.

    Reply
  15. It’s best to pay somebody else younger to do this task. Note, typically the cleaner is just sprayed on and then later washed off so you actually don’t need to get on the roof, just up to roof level.

    Reply
  16. There are other issues with solar PV that are not being addressed. First, no one has yet developed a replacement for ITO for the transparent upper electrode. Solar PV will NEVER scale up cost effectively until such a material is developed. Second, material life time. Does this material have a long lifetime? What about oxidation? If oxidation is a problem (as with the conductive polymers – Plextronics – if they’re still around), then the solar cells have to be hermetically sealed from the atmosphere.

    I will give this credit for the fact it uses Zinc. Zinc is good because Indium is produced as a byproduct of Zinc refining. So, both materials come from the same source. However, this still does not resolve the first problem. Zinc is also non-toxic, unlike for example Cadmium-Tellurium solar cells that are not even allowed in Japan due to the toxicity issue.

    Reply
  17. ‘Oct 23, 2018. Glenorchy Air has suspended its operations out of respect for its founder who died yesterday. The airline said in a statement that Queenstown aviation pioneer Robert Rutherford died last night, after a fall while undertaking property maintenance.’ At 71, he had survived countless flights across the rugged Southern Alps, but died cleaning the solar panels on his roof.

    Reply
  18. I will admit lack of knowledge on solar cell technology. So I fail to see why this is such a breakthrough unless they are able to increase the efficiency of the cell well above 22% the current level of efficiency of cells being mass produced. The cost of installing a typical solar cell system on a house is driven by soft costs and installation cost not the cell costs. SOO installing the most efficient cells if the cost is reasonable makes more sense.

    Reply
  19. ‘Oct 23, 2018. Glenorchy Air has suspended its operations out of respect for its founder who died yesterday. The airline said in a statement that Queenstown aviation pioneer Robert Rutherford died last night, after a fall while undertaking property maintenance.’ At 71, he had survived countless flights across the rugged Southern Alps, but died cleaning the solar panels on his roof.

    Reply

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