Italy-based renewable energy company Enel Green Power, researchers at the National Solar Energy Institute (INES), and the French Alternative Energies and Atomic Energy Commission (CEA) claimed to have achieved a power conversion efficiency of 26.5% for a 2-terminal tandem perovskite solar cell.

The improved efficiency in the collaborative research was obtained for a PIN architecture cell in the device with an active area of 9 cm² and an open-circuit voltage of over 1,880 Mv, with shading correction.

The PIN architecture also helped the collaboration adapt the heterojunction silicon cell produced on the CEA pilot line for its tandem integration.

The researchers said that integrating a P layer allows the deposition of halogenated organometallic perovskite (PK) material without any initial treatment and the optimization of the N-type transport layers.

The collaboration further explored tandem technology to achieve high yields in conventional photovoltaic formats with processes that would allow their industrialization.

The 26.5% efficiency achieved in the above experiment surpassed the earlier conversion efficiencies of 24.9% and 25.8%, achieved on the same active area of 9 cm².

The teams from Enel and CEA are studying the photovoltaic properties of PK materials. They claimed these materials could help achieve conversion efficiencies above 30% by combining them with a lower band-gap material like silicon.

Enel Green Power and its subsidiary 3SUN at Catania in Italy are collaborating with CEA at INES to develop the tandem perovskite-silicon technology with two terminals. A statement by INES said that the work aims to achieve the highest industrially feasible efficiencies in record time.

In the study, the researchers focus on two routes, a NIP-type architecture, wherein they claimed to have achieved a record efficiency of 23.7% on the active surface. The second route, a PIN-type architecture, has been studied since 2021.

Last November, Enel said it intends to build a 3 GW industrial-scale solar module production facility in the United States through its subsidiary 3Sun USA.

In another research, experts at TNO, TU Eindhoven, imec, and TU Delft, partners in Solliance, a solar research institute in the Netherlands, claimed to have pushed the conversion efficiency of tandem solar cells to more than 30%. This efficiency, they said, is beyond the limits of today’s commercial photovoltaic modules and enables more power per square meter and less cost per kWh.