Kaneka presents a 29.2% efficient 2T silicon-perovskite tandem solar cell



Kaneka’s bipolar tandem perovskite solar cell has achieved the highest efficiency ever measured for a device based on an industrial Czochralski (CZ) silicon wafer. It has an open circuit voltage of 1.929 V, a short-circuit current density of 19.5 mA cm−2 and a duty cycle of 77.55%.

The company’s researchers built the cell anti-reflection intermediate layer relying on what they call “easy”. textured structures” that were applied to the front of the base. This is said to allow for a significant improvement in the typical light confinement effects in perovskite-silicon tandem devices.

Light control technology is mandatory to use in full The broad solar spectrum of the solar cell, esp For a 2T tandem structure, because its top and bottom cells are electrically connected in series and required to fill restrictions / current compatibility whereby the respectively The currents at the operating point are somewhat aligned,” they said. “Due to the large difference in refractive indices between perovskite and crystalline silicon (c-Si) materials, the optimizedThe intermediate layer as shown in the picture works as an anti-reFlexion coating, which prevents the reflection loss of infrared light from the bottom cell.”

The company controls the morphology of the soft texture on both sides of the wafer using chemical etching. Through atomic force microscopy (AFM)it compared the performance of two dampers with a gentle structure to the performance of equivalent devices without a structure.
Using gentle structure, luminous flux density The number of silicon base cells increases over from 2% reference,” the company explained.
The company produced a top cell with a substrate made of indium tin oxide (ITO), electron transfer layer made of buckminsterfullerene (C60), passivation layer, perovskite absorber, self-assembled monolayer, ITO-based interlayer and microcrystalline silicon oxide (μc-SiOx). It then fabricated the base cell with an n-doped amorphous silicon layer (:Si), silicon layers processed by several different processes, and a bottom contact made of ITO and silver (Ag).
Passivation layer introduced between C60 and a perovskite layer and The thicknesses of the c-Si wafer and the top ITO layer were reduced this work,” the company explained. “After deposition of the passivation layer, C 60 was sequentially thermally evaporated onto the perovskite film.”

The tandem device achieved power conversion efficiency 29.2%open circuit voltage 1.929 V, a short circuit current density 19.5 mA cm2and a fill coefficient 77.55%. The result, confirmed by Fraunhofer ISE Callab, improves the efficiency of 28.3% that Kaneka had previously achieved with a device with the same architecture, where the main differences are the passivation layer and wafer thickness.

This is the highest certificationfied power conversion efficiency in 2T perovskite-silicon tandem solar cells using CZ According to our knowledge,” the company said, noting that they are currently considering moving to a four-terminal (T4) configuration for further development of the device.

The company introduced a new cell, “High Effective perovskite/heterojunction crystalline silicon tandem solar cells: Towards an industrial-scale cell and module,” which was recently released Japanese Journal of Applied Physics.

Kanela has previously developed the second most efficient solar cell based on crystalline silicon – a 26.63% efficient crystalline silicon solar cell with heterojunction and back contact technology.

*Article title updated to reflect that the cell is a T2 device and not a T4 cell as we previously reported.

David is a passionate writer and researcher who specializes in solar energy. He has a strong background in engineering and environmental science, which gives him a deep understanding of the science behind solar power and its benefits. David writes about the latest developments in solar technology and provides practical advice for homeowners and businesses who are interested in switching to solar.

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