Chinese researchers significantly improve efficiency of perovskite cells

BEIJING, Aug. 8 (Xinhua) -- Chinese researchers have set a new record by increasing the power conversion efficiency of perovskite solar cells up to 25.4 percent, according to a research article recently published in the journal Science.

As the third generation of solar cells, perovskite solar cells feature high efficiency upper limit, low costs and flexible physical properties. They are regarded as a revolutionary new material.

However, the current power generation efficiency of perovskite cells has not yet reached the level of traditional photovoltaic silicon wafers, said Ye Fangyuan, a PhD with the East China University of Science and Technology (ECUST) and also one of the first authors of the research article. Thus researchers are exploring ways to make perovskite cells more efficient.

Many of the hole-transport materials used in inverted perovskite solar cells are either too hydrophobic to wet perovskite precursors or can react with the perovskite, which causes the buried interface between these layers to produce performance-limiting defects.

The researchers from the ECUST reported an amphiphilic molecular hole transporter, phosphonic acid, that forms an extremely wet underlayer for perovskite deposition, which enables high-quality perovskite films with minimized defects at the buried interface.

The resulting perovskite film achieved a power conversion efficiency of 25.4 percent with an open-circuit voltage of 1.21 volts.

The molecular hole transporter is suitable for both perovskite cells and organic polymer solar cells.

In addition to being used for photovoltaic power, perovskite cells can also be used for indoor photovoltaics and wearable devices to facilitate people's life, said Ye.