A wide-bandgap polymer based on the alkylphenylsubstituted benzo[1,2-b:4,5-b0 ]dithiophene unit with high power conversion efficiency of over 11%
Xia Guo ab, Wanbin Li a, Huan Guo a, Bing Guo a, Jingnan Wu a, Wei Ma c, Maojie Zhang *a（张茂杰）and Wai-Yeung Wong *b
a Laboratory of Advanced Optoelectronic Materials, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China.
b Institute of Molecular Functional Materials, Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Hong Kong, China.
c State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049, China
J. Mater. Chem. A, 2018, 6, 16529--16536
A novel wide-bandgap conjugated polymer (PTZP) based on alkylphenyl-substituted benzo[1,2-b:4,5-b′]dithiophene (BDT-P) as the electron-rich unit and thiazolo[5,4-d]thiazole (TTz) as the electron-deficient unit was designed and synthesized for the non-fullerene polymer solar cell (PSCs) application. The polymer exhibited a wide bandgap of 2.01 eV with a strong absorption in the range of 300–620 nm, which was complementary with that of the fused-ring small molecule acceptor (SMA; 2,2′-((2Z,2′Z)-((4,4,9,9-tetrahexyl-4,9-dihydro-s-indaceno[1,2-b:5,6-b′]dithiophene-2,7-diyl)bis(methanylylidene))bis(3-oxo-2,3-dihydro-1H-indene-2,1-diylidene))dimalononitrile, IDIC). Also, the polymer exhibits a deep highest occupied molecular orbital (HOMO) energy level of −5.41 eV. Furthermore, the polymer film possesses strong crystallinity and dominated face-on stacking with a small d-spacing of 3.65 Å, resulting in a high hole mobility of 4.01 × 10−3 cm2V−1 s−1. The optimal PSCs based on the PTZP:IDIC blend showed a high PCE of 11.8% with an open-circuit voltage (Voc) of 0.90 V, a short-circuit current density (Jsc) of 17.9 mA cm−2 and a fill factor (FF) of 73.3%. Moreover, the device with an active layer thickness of up to 200 nm or area of up to 0.81 cm2 exhibited outstanding performance, with PCE of over 10%, resulting from the excellent molecular stacking. These results revealed that PTZP will be a promising conjugated polymer for the fabrication of efficient large-area PSCs.
链接：https://pubs.rsc.org/en/Content/ArticleLanding/2018/TA/C8TA05868G#!divAbstract