In this work, we synthesized a low bandgap polymer polysilole（-2,6-diyl-alt-5-octylthieno[3,4-c]pyrrole-4,6- dione） （PDTSTPD） with different molecular weights （Mn）. The devices based on PDTSTPD/PC71BM composite ...In this work, we synthesized a low bandgap polymer polysilole（-2,6-diyl-alt-5-octylthieno[3,4-c]pyrrole-4,6- dione） （PDTSTPD） with different molecular weights （Mn）. The devices based on PDTSTPD/PC71BM composite are prepared and the dependence of power conversion efficiency （PCE） of the devices on the M,1 of conjugated poly- mers is addressed. We found the hole mobility of PDTSTPD is dependent on the Mn of the polymer, which should be the main reason contributing to the drastic difference of device performance, i.e. the PCE of the device using 10 kDa polymer is only 0.52%, in contrast to 2.3% for 24 kDa polymer device. This PCE data is then further improved to 5.0% via using 1,8-diiodoctane as processing additive to achieve an optimized morphology for the photoactive layer with an appropriate length-scale of phase separation for both exciton dissociation and charge transportation.展开更多
基金Acknowledgement This work was financially supported by the National Natural Science Foundation of China （Nos. 20874100, 20925415, 20990233 and 50921062）, the Solar Energy Initiative （No. KGCX2-YW-399＋9） of the Chinese Academy of Sciences and Hi-Tech Research and Development Program （863） of China （No. 2011AA050524）.
文摘In this work, we synthesized a low bandgap polymer polysilole（-2,6-diyl-alt-5-octylthieno[3,4-c]pyrrole-4,6- dione） （PDTSTPD） with different molecular weights （Mn）. The devices based on PDTSTPD/PC71BM composite are prepared and the dependence of power conversion efficiency （PCE） of the devices on the M,1 of conjugated poly- mers is addressed. We found the hole mobility of PDTSTPD is dependent on the Mn of the polymer, which should be the main reason contributing to the drastic difference of device performance, i.e. the PCE of the device using 10 kDa polymer is only 0.52%, in contrast to 2.3% for 24 kDa polymer device. This PCE data is then further improved to 5.0% via using 1,8-diiodoctane as processing additive to achieve an optimized morphology for the photoactive layer with an appropriate length-scale of phase separation for both exciton dissociation and charge transportation.
