Renewable Energies Highly efficient perovskite solar cell developed in China

Related Vendors

FAULHABER Drive Systems

dataTec AG

Wuxi InfiMotion Technology Co., Ltd.

The search for alternatives to silicon solar cells continues, and Chinese researchers have just made a breakthrough. Specifically, they have developed a perovskite solar cell with new materials that sets a new efficiency record.

Henrik Bork, a long-standing China correspondent for German Süddeutsche Zeitung and Frankfurter Rundschau, is Managing Director at Asia Waypoint, a consulting agency based in Beijing that specializes in China. "China Market Insider" is a project of  Vogel Communications Group, Würzburg/Germany.

The team of Yi Chenyi at the Tsinghua University in Beijing has developed a perovskite solar cell with new HTM materials that sets a high-efficiency record of 26.41 percent for this type of cells, the researchers report in a globally recognized professional journal.

Perovskite - promising but far from market-ready

Perovskite is a mineral with a typical crystal structure, and solar cells based on it are considered a promising technological route for photovoltaics, because their production is relatively cheap and simple. However, a number of problems need to be solved - including efficiency and better cell longevity - before they can be mass-produced and commercially compete with silicon cells.

The team in China, which also included researchers from the University of Ferrara in Italy and the Zurich University of Applied Sciences (ZHAW), developed a new multifunctional HTM ("hole transporting material") that, combined with a vacuum evaporation production method, has proven to be particularly effective for efficiency in solar cells. They named the new material "T2".

The excellent performance combined with scalable and cost-effective synthesis provides a solid foundation for future applications of perovskite solar cells on a large scale.

Forscherteam um Yi Chenyi, Qinghua-Universität, Peking

The energy conversion efficiency in prototypes of a solar cell reached "26.41 percent (26.21 percent certified) and 24.88 percent (certified)" in their experiments, write Yi Chenyi and his team members in the Joule magazine. "The outstanding performance, combined with scalable and cost-effective synthesis, lays a solid foundation for future applications of perovskite solar cells on a large scale," write the Chinese scientists in their article.

New material is more powerful and cheaper

Their new T2 material is based on a "thiomethyl-substituted fluorene arm and spiro-(fluorene-9,9´-xanthene) core," report the Chinese researchers. This is more powerful and also cheaper than the most commonly used spiro-OMeTAD, they claim.

The uniqueness of the new material lies in its ability to slow down the ion migration between the various layers of the solar cell. This allows for a better extraction of the positive "holes" that are left after the electrons are extracted by sunlight, according to the scientists.

Perovskite solar cells are a relatively young technology that was only invented in 2009. However, since then, research has been conducted worldwide to improve them, as there is a large and growing market for more powerful and cost-effective solar cells.

Prototypes with larger areas are planned

The team around Yi Chenyi at the Department of Electrical Engineering at Qinghua University (also known as Tsinghua Uni) now plans to test prototypes with larger areas in the next step. So far, only a surface of 0.1 square centimeters has been used.

This is necessary because many problems are still unresolved. One of the drawbacks of perovskite crystals is that they can grow uncontrollably, which affects the stability of solar cells. Among other reasons, PSC (perovskite solar cells) are so far not durable enough for industrial use. Also, most of the prototypes developed so far show high efficiency losses within the first few months.

As quickly as possible to commercial mass production

The team leader in Beijing plans for his team to "focus on continuous breakthroughs in issues such as efficiency loss and long-term stability" in the next step "after expanding the cell area," reports the daily newspaper Beijing Ribao.

The goal of Chinese researchers is definitely to prepare for a commercially viable mass production of perovskite solar cells as quickly as possible, writes the daily newspaper in Beijing. Therefore, the high focus of Chinese researchers on application problems and industrial practice is also noticeable in this specific case.