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 tandem device achieved power conversion efficiency 29.2%open circuit voltage 1.929 V, a short circuit current density 19.5 mA cm−2and 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.