Polymer Solar Cell Special Seminar

Monday, August 26, 2013 2:00-4:00 PM

Room B401 @ KI Building

Molecular design of conjugated polymers and their applications in highly

efficient polymer solar cells

Prof. Jianhui Hou, Institute of Chemistry, Chinese Academy of Sciences, Beijing

Polymer solar cell (PSC) has attracted much attention due to its potential application in production of large area, light weight and flexible panels. In order to improve power conversion efficiency (PCE) of PSC, more and more new materials were designed and synthesized and their properties, like molecular energy levels and band gaps, can be tuned effectively. In these new materials, benzo[1,2-b:4,5-b’]dithiophene (BDT) based conjugated polymers exhibited promising photovoltaic properties.

In this presentation, photovoltaic properties of BDT-based conjugated polymers were tuned through molecular structure design. Functional groups or conjugated components with strong electron-withdrawing effect were introduced into the BDT-based polymers, and HOMO level of the BDT-based polymers can be lowered effectively without sacrificing absorption area and hole mobility. Therefore, higher open circuit voltage (Voc), good short circuit voltage (Jsc) and fill factor (FF) were recorded, and hence high PCE can be realized. These results indicate that two-dimensional structure is an effective way to enhance photovoltaic properties of the BDT-based conjugated polymers. Moreover, Hou will also present a few interesting recent works. For example, a new polymer showing highly efficient photovoltaic performance with low polymer content in D/A blend was designed and based on this polymer, an interesting mechanism of charge transport in PSC was suggested and discussed; a new polymer showing very compact laminar packing was designed and this polymer shows optimized efficiency under high polymer content.

In conclusion, we will share our recent progress and interesting findings about material design of photovoltaic polymers.