Enhancing performance in two-terminal tandem solar cells

Feb 21, 2022 01:22 PM ET
  • Solar photovoltaics (PV) is a significant stepping-stone in our shift towards a sustainable energy economic climate. The International Renewable Energy Agency (IRENA) roadmap suggests that by 2050, power generation from PV ought to reach 43 percent of the overall installed power capacity. This can be turned into reality by reducing the cost of PV systems as well as raising the efficiency of solar cells, which would allow massive setups of compacts PV.
Enhancing performance in two-terminal tandem solar cells
Image: solardaily.com

To this end, a current research study released in the Journal of Photonics for Energy (JPE) checks out the performance gain given by tandem solar cells in which several semiconductors with different energy spaces are piled atop each other, with a spectral splitter introduced in between the top as well as bottom terminals.

Why this specific design? It ends up that tandem solar cells are sensitive to a wider region of the sunshine's range. This level of sensitivity allows them to gather light successfully and also possibly get to a general effectiveness more than the theoretical limit of conventional solar cells.

However, they generally struggle with ineffective light trapping as well as monitoring caused by parasitical light absorption in non-active layers and reflection in between layers. Recent studies have actually dealt with these problems, yet the concept of distributing sunshine in the tandem subcells with controlled spectral splitting is underexplored.

This is where a team of scientists from The Netherlands, who did the research, is available in. They designed a two-terminal tandem solar cell with a perovskite top cell and silicon bottom cell and also placed spectral splitters between them. "In PV study, every number that can be gained in cell effectiveness is essential.

Adding a range splitting interlayer can help us gather the maximum present as well as voltage by splitting the incident sunlight into reduced- and also high-energy spectral bands and dispersing them efficiently among the top and bottom cells," describes Albert Polman of NOW-Institute AMOLF, who led the study.

Polman keeps in mind that introducing spooky splitters can likewise result in cheaper solar cells, greater throughput in manufacture, and also reduced poisoning per unit cell area. Furthermore, they can broaden the extent of tandem cells for applications in photoelectrochemical splitting of water.

Polman's group taken into consideration 2 sort of spectral splitters, namely "planar" as well as "Lambertian" splitters, in their research. The planar splitter imitates a mirror, mirroring the light straight back to the leading cell to allow it to be absorbed there. On the other hand, the Lambertian splitter mirrors light in an angular style to make sure that it needs to finish a lot longer path through the solar cell, and also for this reason can be soaked up much more easily.

According to their estimations, in the existence of a spectral splitter, industrially suitable leading cells with energy voids of 1.7 eV and greater showed a 5 to 6 percent gain in absolute effectiveness in the limit of unlimited thickness for a 500 nm thick top cell. In addition, their forecasts disclosed that selecting a Lambertian spooky splitter over a planar splitter substantially improves the performance enhancement.

While the group's research study is theoretical, the outcomes are economically fascinating. Supplied there is no considerable splitting efficiency loss with upscaling, and also the construction steps are of similar expenses, the effectiveness gain per layer of the perovskite/silicon tandem with a Lambertian spooky splitter is within an economically competitive range.

Siva Sivoththaman, Associate Editor of JPE and also Supervisor of the University of Waterloo's Centre for Advanced Photovoltaic Gadgets, notes that the paper makes a timely and unique payment to photovoltaic cell architectures based on perovskite/silicon tandems.

More specifically, "The concept advanced on ingrained spectrum splitters is in theory shown to cause significant performance gains, pushing the thermodynamic limits up. Although an academic work, speculative criteria were made use of to accurately show how the Lambertian spooky splitter advantages structures with high-bandgap top cells."

Solar cells might still have a long way to precede they replace conventional energy sources. However this research provides expect their success in the future.

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