New type of solar cells efficiently use near-infrared light energy

Professor Xiong Yujie of the University of Science and Technology of China, based on a widely used semiconductor silicon material, adopts a thermal electron injection method of metal nanostructures to design a solar cell that can perform photoelectric conversion in the near-infrared region and has mechanical flexibility. The research results have recently been published online in the German Journal of Applied Chemistry, an important international chemical journal.

At present, most solar cells are absorbed by visible light, and near-infrared light, which accounts for 52% of sunlight, has not been efficiently used. To address this issue, Xiong Yujie’s research group creatively integrated silver nanoplates with near-infrared light absorption properties with silicon nanowires based on previously researched semiconductor-metal interfaces, and constructed two different photovoltaic devices, a near-infrared region. Photoelectric conversion performance has been improved. Under the near-infrared light, the hot electrons generated by the silver nanosheets can be directly injected into the silicon semiconductor, and the photoelectric conversion efficiency in this waveband is increased by 59%.

In addition, traditional solar cells must be processed into hard plate-like objects, which limits daily use. The flexible device is light in weight and can be folded, curled, and stuck on curved surfaces such as automotive glass, roofs, clothes, and the like. Xiong Yujie's research group carried out nano-processing of commercial silicon wafers, combined with the near-infrared light absorption performance of silver nano-sheets, to produce near-infrared solar cells with mechanical flexibility.

Experts said that the work achieved an effective combination of nano-manufacturing and nano-synthetic nanotechnology to realize a composite structure interface design with broad-spectrum light absorption, and developed a simple and effective method for manufacturing near-infrared flexible solar cells that would be promising. For the development of intelligent temperature-controlled solar cells and wearable solar cells. (Reporter Wu Changfeng correspondent Yang Baoguo)