High-performance nonfullerene polymer solar cells based on a fluorinated wide bandgap copolymer with a high open-circuit voltage of 1.04 V
Yan Wang‡, Qunping Fan‡, Xia Guo*（国霞）, Wanbin Li, Bing Guo, Wenyan Su, Xuemei Ou and Maojie Zhang *（张茂杰）
State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials, Laboratory of Advanced Optoelectronic Materials, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123,
‡ These authors contributed equally to this work.
J. Mater. Chem. A, 2017, 5, 22180--22185
In this work, efficient nonfullerene (NF) polymer solar cells (PSCs) based on a polymer donor PM6 containing a fluorinated-thienyl benzodithiophene unit and a small molecule acceptor ITIC were developed. PM6 possesses a strong absorption in the short wavelength region of 300–685 nm with a large bandgap of 1.80 eV, which is complementary to that of ITIC (1.55 eV) and facilitates achieving high short-circuit current (Jsc) in PSCs. Moreover, PM6 shows a deep HOMO level of −5.50 eV, a strong crystallinity and a dominant face on packing, which helps to achieve a high open-circuit voltage (Voc) and fill factor (FF) in PSCs. As a result, the PM6:ITIC-based PSCs obtained a power conversion efficiency (PCE) of 9.7% with a Voc of up to 1.04 V, a Jsc of 16.0 mA cm−2 and a FF of 58%, under the illumination of AM 1.5G, 100 mW cm−2. Notably, the energy loss (Eloss) of the PSCs is as low as 0.51 eV, which is smaller than the empirically low threshold of 0.6 eV. The PCE of 9.7% is one of the highest values reported in the literature for PSCs with a Voc over 1.0 V and an Eloss less than 0.55 eV.
链接：http://pubs.rsc.org/en/content/articlelanding/2017/ta/c7ta07785h#!divAbstract