The effects of rubbing-induced nanostructure in polymer solar cell

Compared with other solar cells, polymer solar cells have been widely noted due to the advantages including: easy fabrication, low cost, light, large area fabrication, and flexibility. It is an important research direction that fabricating nanostructure on differ-ent layer to enhance the efficiency. In this thesis, we adopt rubbing process, which is a low cost, simple and size-unlimited process, to produce nanostructure on PEDOT:PSS and active layer respectively, and execute some measurements to propose the reasons of efficiency enhancement.

First of all, for the comparison of the effects of rubbing process, it is necessary to build up a standard fabrication of polymer solar cells. After some factors testing, in-cluding the choice of ITO film thickness, the use of filter, and the annealing temperature, we successfully established a stable fabrication process of standard polymer solar cells.

Second, we introduced rubbing process into the fabrication of polymer solar cells. We produced nanostructure on PEDOT:PSS layer, and enhanced the conversion effi-ciency from 0.82 % to 1.28 % in our lab. For further understanding of this effect, we cooperated with Prof. Wang, and successfully enhanced the conversion efficiency from 3.45 % to 3.82 %. It revealed that rubbing process could be applied in different system. In addition, we used Atomic Force Microscope to prove the presence of nanostructure on PEDOT:PSS layer. We also measured the absorption spectrum, photoluminescence, X-ray diffraction, and hole mobility to certificate that rubbing-induced nanostructure could enhance light absorption, reduce recombination, increase hole mobility, and en-hance the crystallinity of PCBM.
Finally, we used rubbing process to produce nanostructure on active layer, and we successfully enhanced the efficiency from 0.82 % to 1.20 %. Further research about this issue will be completed in the future.

In conclusion, we have introduced rubbing process to the fabrication of polymer solar cells, and produced nanostructure to enhance the conversion efficiency. The ad-vantages of rubbing process are identical with polymer solar cells. Coupled with the feasibility of multilayer fabrication, it has large potential to benefit the commercializa-tion of polymer solar cells.