Chinese scientists have developed high-performance flexible organic solar cells

Professor Chen Yongsheng and his team from the School of Chemistry of Nankai University have made a breakthrough in the research of flexible transparent electrodes and flexible organic solar cells, according to a paper published by Nature Electronics, a leading academic journal of Nankai University.


Chen Yongsheng's team prepared flexible transparent electrodes of silver nanowires with high conductivity, high light transmittance and low surface roughness, which were used to build flexible organic solar cells. The performance of the devices using commercial indium tin oxide (ITO) glass electrodes was comparable, and the photoelectric conversion efficiency could reach 16.5%. The highest photoelectric conversion efficiency of flexible organic/polymer solar cells has been reported in the literature. The results bring efficient flexible organic solar cells one step closer to commercialization.


Flexible electronic devices, especially optoelectronic devices based on organic materials, are a major trend of the development of electronic devices in the future and have a great application prospect.


"Among them, obtaining the flexible transparent electrode with high performance is the premise to realize the efficient flexible organic optoelectronic devices, and it is also the core problem in this field. However, how to obtain flexible and transparent electrodes with high conductivity, high light transmittance, low surface roughness and a simple and green preparation method remains a huge challenge." Chen Yongsheng said.


Due to the lack of flexible transparent electrodes, the performance of flexible organic optoelectronic devices is still far behind the corresponding rigid devices. Flexible transparent electrodes are usually prepared by dry process (such as evaporation) or solution process (such as slit printing, nano-imprint or electrospinning). Compared with the dry method, the solution treatment method has the advantages of low cost, large scale printing and so on, and has great development potential.


Chen's team prepared flexible and transparent silver nanowire electrodes with a "meshlike" structure using a polymer electrolyte. The flexible transparent electrode has achieved excellent performance, low surface roughness, excellent mechanical properties and thermal stability, and the preparation method is simple and green.


To prove its practicability in organic photoelectric devices, Chen's team prepared flexible organic solar cells based on the flexible transparent electrode. The results show that the electrode can be applied to different types of active materials, single junction and laminated photovoltaic devices. Single junction and laminated flexible organic solar cells can achieve photoelectric conversion efficiency of 13.1% and 16.5%, respectively, and exhibit excellent mechanical properties. The device can still maintain over 95% of the initial efficiency after continuous bending for 1000 times.


"In addition to applications in organic solar cells, this low-cost, high-performance flexible transparent electrode will also have great potential for applications in organic light-emitting diodes, transistors, sensors and other fields." Chen Yongsheng said. (after)