A n-type organic semiconductor (n-OS) electron acceptor (ITCNTC) based on thieno [2,3-b]thiophene-containing asymmetric seven fused-ring central unit was developed. In comparison with the reported isomer of ITCPTC, ITCNTC exhibits blue-shift absorption spectra and higher LUMO energy level. Organic solar cells (OSCs) based on wide band-gap polymer donor J71 and ITCNTC blends gave power conversion efficiencies (PCEs) of 5.18% without any post-treatment. After thermal annealing (TA), PCE was significantly boosted to 8.52%, with enhanced short circuit current density (J_SC) and fill factor (FF). However, the PCE of 8.52% is lower than that of the reported J71:ITCPTC based device (11.63%), which is mainly ascribed to the narrower absorption of ITCNTC and unfavorable morphology. It is noteworthy that the average open circuit voltage (V_OC) of the ITCNTC-based device (0.940 V) is 0.06 eV higher than that of the ITCPTC-based device (0.877 V), which is benefitted from the upshifted LUMO energy level of ITCNTC acceptor. These results indicate that the chemical structure of the central fused ring plays a very important role in determining the photovoltaic performance of the n-OS acceptors.

开发了基于含噻吩并[2,3 - b ]噻吩的不对称七个稠环中心单元的n型有机半导体（n -OS）电子受体（ITCNTC）。与报告的ITCPTC异构体相比，ITCNTC表现出蓝移吸收光谱和更高的LUMO能级。基于宽带隙聚合物供体J71和ITCNTC共混物的有机太阳能电池（OSC）无需任何后处理即可获得5.18％的功率转换效率（PCE）。经过热退火（TA）后，PCE显着提高到8.52％，短路电流密度提高了（J _SC）和填充因子（FF）。但是，PCE为8.52％，低于已报道的基于J71：ITCPTC的器件的PCE（11.63％），这主要归因于ITCNTC的吸收范围较窄和形态不利。值得注意的是，平均开路电压（V _OC基于ITCNTC设备（0.940 V）的）是0.06 eV的比基于ITCPTC设备（0.877 V），这是从换高档LUMO能级受益的更高ITCNTC受体。这些结果表明中心稠合环的化学结构在确定n -OS受体的光伏性能中起着非常重要的作用。