Chongqing Institute of Green and Intelligent Technology , Chinese Academy of Sciences , Chongqing 400714 , China.
Key Laboratory of Optoelectronic Technology and Intelligent Control of Education Ministry , Lanzhou Jiaotong University , Lanzhou , Gansu 730070 , China.
ACS Appl Mater Interfaces. 2019 Feb 20;11(7):6717-6723. doi: 10.1021/acsami.8b20567. Epub 2019 Feb 8.
Nonfullerene acceptors (NFAs) based on calamitic-shaped small molecules are being developed rapidly to improve the photoelectron conversion efficiencies (PCEs) of organic solar cells. NFAs with light absorption extended to the near-infrared (NIR) region are of interest because they play a pivotal role in both organic tandem cells and semitransparent devices. In this work, two simple acceptor-donor-acceptor-structured NFAs (CPDT-4Cl and CPDT-4F) have been designed and synthesized. Featured with dimerized 4H-cyclopenta[1,2-b:5,4-b']dithiophene (CPDT) as the electron-donating core and Cl- or F-substituted 2-(3-oxo-2,3-dihydro-1H-inden-1-ylidene)malononitrile as the electron-accepting unit, the absorption spectra of two NFAs are extended to the NIR region with an absorption edge at approximately 910 nm. In conjunction with the polymer donor material PBDB-T, a PCE of 9.47% was achieved by using a CPDT-4F-based device with a short-circuit current density of up to 20.1 mA/cm, which slightly outperforms its counterpart CPDT-4Cl (PCE = 9.28%) under the same condition. This work broadens the scope of developing new NIR NFAs with both high efficiency and easy accessibility.
基于棒状小分子的非富勒烯受体 (NFA) 正在迅速发展，以提高有机太阳能电池的光电转换效率 (PCE)。对具有扩展到近红外 (NIR) 区域的光吸收的 NFA 感兴趣，因为它们在有机串联电池和半透明器件中都起着关键作用。在这项工作中，设计并合成了两种简单的给体-受体-给体结构的 NFA（CPDT-4Cl 和 CPDT-4F）。以二聚化的 4H-环戊并[1,2-b:5,4-b']二噻吩 (CPDT) 作为电子供体核，Cl-或 F-取代的 2-(3-氧代-2,3-二氢-1H-茚-1-亚基)丙二腈作为电子受体单元，两个 NFA 的吸收光谱扩展到 NIR 区域，吸收边缘约为 910nm。与聚合物给体材料 PBDB-T 结合，使用基于 CPDT-4F 的器件实现了 9.47%的 PCE，短路电流密度高达 20.1 mA/cm，在相同条件下略优于其对应物 CPDT-4Cl（PCE = 9.28%）。这项工作拓宽了开发具有高效率和易于获得性的新型 NIR NFA 的范围。
