四川大学からの留学生 Daobin Yang君、M2 溝井君の非対称SQを用いた有機薄膜太陽電池の論文が J. Mater. Chem. A にアクセプトされました。Yang君、溝井おめでとう！
Cyano-Substitution on the End-Capping Group: A Facile Access Toward Asymmetrical Squaraine Showing Strong Dipole-Dipole Interactions as High Performance Small Molecular Organic Solar Cells Material
Daobin Yang,a,b Yan Jiao,a Lin Yang,a Yao Chen,a Satoshi Mizoi,b Yan Huang,*a Xuemei Pu,a Zhiyun Lu,a Hisahiro Sasabe*b and Junji Kido*b , J. Mater. Chem. A accepted.
Abstract: A novel asymmetrical squaraine derivative bearing cyano-substituted indoline end-capping group, namely ASQ-5-CN, was designed and synthesized. In comparison with the noncyano-substituted ASQ-5, ASQ-5-CN shown an analogous absorption band-gap in thin solid film state, but a 0.11 eV lowered HOMO energy level, which leads to a higher Voc. Density functional theory calculation results revealed that the dipole moment of ASQ-5-CN was two times larger than that of ASQ-5. Hence the stronger dipole-dipole interactions of ASQ-5-CN may trigger more intense intermolecular packing in ASQ-5-CN, which should account for the higher hole-mobility of ASQ-5-CN than that of ASQ-5 (4.00 ×10-5 vs. 1.67 ×10-5 cm2 V-1 s-1). Accordingly, solution-processed bulk-heterojunction small molecular organic solar cell using ASQ-5-CN as electron donor material exhibited much higher PCE (5.24%) than that of the reference compound ASQ-5-based device (4.22%) due to its simultaneously enhanced Voc (0.92 vs. 0.82 V), Jsc (11.38 vs. 10.94 mA cm-2) and FF (0.50 vs. 0.47). Additionally, the PCE of the ASQ-5-CN-based device could be improved to be as high as 6.11% when measured at 80 °C, which is the record PCE among the hitherto reported squaraine-based solution-processed small molecular organic solar cells.
