Research has found that perovskites may be combined with silicon-based semiconductors to create “tandem” solar cells that can surpass the maximum theoretical efficiency of silicon solar cells.

This could further enable solar cells to be two to four times cheaper when compared to thin-film solar cells.

While perovskites can be produced at lower temperatures, making solar energy technologies cheaper and more environmentally friendly, they are less efficient when exposed to heat, moisture, and air. So, the lifespan of perovskite currently is too short to be commercially competitive in solar panels.

To prevent perovskite semiconductors from degrading quickly, a team at the University of Michigan, in their latest study published in the journal Matter, have found a way to make the perovskite film last longer.

“Silicon solar cells are great because they are very efficient and can last for a very long time, but the high efficiency comes with a high cost. To make high-purity silicon, temperatures over 1,000 degrees Celsius are needed. Otherwise, the efficiency won’t be as good,” said Xiamen Gong, assistant professor of chemical engineering.

This research aims to make perovskite solar cells harder and suggests how bulky molecules are best at increasing the perovskites’ stability and overall lifespan.

To do this, the team created three additives with various shapes and sizes and added them into thin films of perovskite crystals, which can absorb light and convert it to electricity. They measured how strongly the different additives interacted with perovskites and consequently influenced the formation of defects in the films. They found that perovskite films heated to over 200 degrees Celsius confirmed that bulky additives helped the films retain more of their characteristic slate-black color and develop fewer structural defects.

Last July, scientists from IIT-Bombay found that the tandem approach can combine both the perovskite and silicon solar cells to attain enhanced efficiency.

The National Renewable Energy Laboratory also found a scalable solution in one-step coating that can increase the commercialization of perovskite solar cells.