Recently, Yongye Liang’s research group has developed an efficient molecular engineering approach for the improvement of efficiency and accessibility of polymer solar cells (PSCs). This work (“Molecular Engineering on Conjugated Side Chain for Polymer Solar Cells with Improved Efficiency and Accessibility”) has been published online by the journal Chemistry of materials (impact factor: 9.407) of American Chemical Society.

PSC is an emerging photovoltaic technology, which possesses the potential for a variety of applications in modern life, such as semi-transparent solar windows and flexible electronic devices. The power conversion efficiency (PCE) of PSCs has exceeded 10%, which is comparable to that of thin film silicon. Besides photovoltaic performance, cost of materials and device fabrication process are among the key factors for PSCs to become a practical solar harvesting technology.

Here, Liang’s group report a facile molecular engineering approach with 4-methoxy modified thiophene as the conjugated side chain for polymer donors to afford both lower highest occupied molecular orbital (HOMO) energy levels and enhanced interchain interactions. This approach features enhanced Voc and hole mobility with simplified material preparation simultaneously. High performance PSCs are demonstrated with PCEs over 9.2% from halogenated solvents in a representative polymer, PMOT5. Further, PSCs processed from a non-halogenated solvent without any additives can achieve a PCE exceeding 8 %，which is among the highest efficiency for PSCs processed from an environmental friendly solvent at ambient temperature and without any additives. 

The first author of this paper is Xing Zhang. Coauthors include Meilin Li, Luozheng Zhang, Tingbin Yang, Zhi Zhang, Hao Zeng, Xing Zhang and Prof. Li Dang. This work was supported by s “The Recruitment Program of Global Youth Experts of China”, National Science Foundation of China and the Shenzhen fundamental research programs, Shenzhen Key Lab funding and Peacock Plan.

Link: http://pubsdc3.acs.org/doi/full/10.1021/acs.chemmater.6b02381