Increasing solar cell efficiency: innovative techniques improve silicon-perovskite interaction, but the challenge of scaling up for widespread commercial application still looms.

Engineers focusing on solar power, one team from Helmholtz-Zentrum Berlin für Materialien und Energie GmbH and another from École Polytechnique Fédérale de Lausanne, have developed two distinct methods to enhance the efficacy of solar cells.

They achieved this by facilitating a better collaboration between silicon and perovskite. Their research, tests, and results have been documented and shared in the Science journal.

An analytical piece on the efforts of both teams was also penned by Stefaan De Wolf and Erkan Aydin from the King Abdullah University of Science and Technology and published in the same journal issue.

It’s known from previous studies that the potential efficiency of silicon is capped at 29.4% due to its inability to convert more than a small fraction of sunlight frequency band into electricity.

To navigate this issue, solar engineers have been exploring the use of other materials, in an additional layer, capable of converting different light frequencies into electricity.

Perovskite is one such material. It’s a crystal produced from a blend of titanium and calcium.

While it has shown potential, its usefulness is constrained because it permits certain electrons to be reabsorbed back into the crystal, hence, preventing their use in electricity generation. Both the teams have now addressed this issue, but each through a unique method.

In the first strategy, the engineers introduced liquid piperazinium iodide into an already applied layer of perovskite on silicon. Their approach was shown to achieve an efficiency of 32.5% during tests.

For the second method, the team devised a procedure that involved applying precursor chemicals onto a silicon layer and then adding another chemical that triggered a reaction resulting in the creation of a perovskite layer. This produced a coating with fewer defects, thereby reducing the chance for electrons to return to the crystal.

The two-step method demonstrated an efficiency of 31.2% in solar cells.

However, both groups recognize that their methods have been tested on smaller solar cells than those in commercial use. Therefore, a strategy for scaling up these techniques is required before they can be employed in conventional solar-cell applications.

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Publication Referenced in the Article:

Xin Yu Chin et al, Interface passivation for 31.25%-efficient perovskite/silicon tandem solar cells, Science (2023). DOI: 10.1126/science.adg0091

Silvia Mariotti et al, Interface engineering for high-performance, triple-halide perovskite–silicon tandem solar cells, Science (2023). DOI: 10.1126/science.adf5872

Stefaan De Wolf et al, Tandems have the power, Science (2023). DOI: 10.1126/science.adi6278

This article has been adapted from source material published by Tech Xplore.