Recently, Yongsheng Chen and his group have made an unprecedented progress in the research of organic solar cells. They construct a tandem organic solar cell characteristic of absorbing a broader part of the solar spectrum using complementary absorptive subcells to minimize the thermalization loss of photon energy. The optimized devices achieve a power conversion efficiency of 12.50% (verified 12.70%), which represents a new level of capability for solution-processed, organic solar cells.

The research paper introducing the achievement was published on the national journal, Nature Photonics on Dec. 5th.

Organic solar cell, as one of the effective methods to manage environmental pollution as well as energy crisis, is far better than traditional solar cell for its low cost, flexibility, simple process and environmental friendliness. It applies photosensitive organic materials including polymer as semiconductor, producing voltage through photovoltaic effect to generate current. However, improving power conversion efficiency has always been a problem since the first occurrence of organic solar cell, and the issue also determines its practical application in daily life.

“As a new research field, organic solar cell in recent years has been benefiting from the development of materials with photoactive layer and the refinement of devices,” says Chen.

Researchers of the group point out that according to the related theory, there’s still room for the improvement of various indicators such as power conversion efficiency of organic solar cells by means of further refining the materials and devices. And in the near future, the conversion efficiency is expected to reach beyond 15%. “Our next step is to enhance the life of the cell and to further increase its efficiency. We believe that in the near future organic solar cell will be put into practical use,” says Chen.

The research has received close support from Ministry of Science and Technology of the PRC, the National Natural Science Foundation, Tianjin Municipal Science and Technology Commission and Nankai University.