The National Research Foundation of Korea announced on Dec. 23 that Kyungpook National University professor Kim Young-kyu’s research team has developed a technique for forming nanometer-scale dots on an electron collection layer, and this technique allows high-efficiency organic solar cells to be manufactured through a simple process.
Organic solar cells, which generate energy by receiving sunlight via organic semiconductors, are excellent in optical absorption and can be manufactured with ease. However, these have had safety issues with regards to the high level of acidity of the material used as positive hole-collecting layers. Under the circumstances, countries around the world are working on inverted-type elements so that positive holes and charges are collected in the opposite direction by the use of a metal oxide-coated electron collection layer instead of the acidic material.
The research team coated the metal oxide-coated electron collection layer of the inverted-type organic solar cell element with a polymeric PEOz solution that has a certain concentration and succeeded in forming multiple polymeric nanodots. These dots can facilitate charge transport and adhesion between organic semiconductors and metal oxides, which results in the collection of more electric charges.
“What we have developed at this time has achieved an efficiency of 10.74 percent, the highest level in the world for single-layer organic solar cells,” the professor explained, adding, “Its improved adhesion properties will contribute to the service life of organic solar cell elements as well.” He continued to say, “In addition, it can be manufactured in a simpler, cheaper and more efficient way than existing metal oxide coating materials, and thus will be able to accelerate the commercialization of organic solar cells.”
Details of the research are available on the online edition of the Nature Communications released on Dec. 14.