Fullerene-free Polymer solar cells manufactured using low-cost printing technology sets a new world record

Researchers at Linköping University and the Chinese Academy of Sciences (CAS) have developed cheaper and more reliable polymer solar cells.

In recent years, polymer solar cells have emerged as a low cost alternative to silicon solar cells. In order to obtain high efficiency, fullerenes are usually required in polymer solar cells to separate charge carriers. However, fullerenes are unstable under illumination, and form large crystals at high temperatures.

A team of researchers led by Professor Jianhui Hou at the CAS has set a new world record for fullerene-free polymer solar cells by developing a unique combination of a polymer called PBDB-T and a small molecule called ITIC. This combination converts solar energy with an efficiency of 11%.

Feng Gao with his colleagues Olle Inganäs and Deping Qian at Linköping University, have characterized the loss spectroscopy of photovoltage (Voc), a key figure for solar cells, and proposed approaches to further improving the device performance.

Researches will be presenting their results in the high-profile journal Advanced Materials.

“We have demonstrated that it is possible to achieve high efficiency without using fullerene, and such solar cells are also highly stable to heat. Because solar cells are working under constant solar radiation, good thermal stability is very important,” said Feng Gao, a physicist at the Department of Physics, Chemistry and Biology, Linköping University. He further added “the combination of high efficiency and good thermal stability suggests that polymer solar cells, which can be easily manufactured using low-cost roll-to-roll printing technology, now come a step closer to commercialization.”