Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology , Wuhan, 430074, China.
School of Material Science and Technology, Guangxi Key Laboratory of Information Materials, Guilin University of Electronic Technology , First Jinji Road, Guilin, Guangxi 541004, China.
ACS Appl Mater Interfaces. 2017 Feb 22;9(7):6615-6623. doi: 10.1021/acsami.6b15424. Epub 2017 Feb 9.
An interface stabilizer based on alkylation-functionalized fullerene derivatives, [6, 6]-Phenyl-C61-butyric acid (3,5-bis(octyloxy)phenyl)methyl ester (PCB-C8oc), was successfully synthesized and applied for the active layer of Organic Photovoltaics (OPVs). The PCB-C8oc can replace part of the phenyl-C61-buty-ric acid methyl ester (PCBM) and be distributed on the interface of poly(3-hexylthiophene) (P3HT) and PCBM to form P3HT/PCBM/PCB-C8oc ternary blends, leading to thermally stable and efficient organic photovoltaics. The octyl groups of PCB-C8oc exhibit intermolecular interaction with the hexyl groups of P3HT, and the fullerene unit of PCB-C8oc are in tight contact with PCBM. The dual functions of PCB-C8oc will inhibit the phase separation between electron donor and acceptor, thereby improving the stability of devices under long-time thermal annealing at high temperature. When doped with 10 wt % PCB-C8oc, the power conversion efficiency (PCE) of the P3HT system decreased from 3.54% to 2.88% after 48 h of thermal treatment at 150 °C, whereas the PCE of the reference device without PCB-C8oc dramatically dropped from 3.53% to 0.73%. When doping 10 or 20 wt % PCB-C8oc, the unannealed P3HT/PCBM/PCB-C8oc device achieved a higher PCE than the P3HT/PCBM device without any annealing following the same fabricating condition. For the PTB7/PCBM-based devices, after adding only 5 wt % PCB-C8oc, the OPVs also exhibited thermally stable morphology and better device performances. All these results demonstrate that the utilization of alkyl interchain interactions is an effective and practical strategy to control morphological evolution.
一种基于烷基化功能化富勒烯衍生物的界面稳定剂，[6,6]-苯基-C61-丁酸（3,5-双（辛氧基）苯基）甲酯（PCB-C8oc），被成功合成并应用于有机光伏器件（OPVs）的活性层。PCB-C8oc 可以替代部分苯基-C61-丁酸甲酯（PCBM），分布在聚（3-己基噻吩）（P3HT）和 PCBM 的界面之间，形成 P3HT/PCBM/PCB-C8oc 三元共混物，从而得到热稳定和高效的有机光伏器件。PCB-C8oc 的辛基与 P3HT 的己基之间存在分子间相互作用，而 PCB-C8oc 的富勒烯单元与 PCBM 紧密接触。PCB-C8oc 的双重功能将抑制电子给体和受体之间的相分离，从而提高器件在高温长时间热退火下的稳定性。当掺杂 10wt%的 PCB-C8oc 时，P3HT 体系在 150°C 下热处理 48 小时后，功率转换效率（PCE）从 3.54%降至 2.88%，而没有 PCB-C8oc 的参考器件的 PCE 则从 3.53%急剧降至 0.73%。当掺杂 10 或 20wt%的 PCB-C8oc 时，未经退火的 P3HT/PCBM/PCB-C8oc 器件在相同的制备条件下，其 PCE 高于未经任何退火的 P3HT/PCBM 器件。对于基于 PTB7/PCBM 的器件，仅添加 5wt%的 PCB-C8oc 后，OPVs 也表现出热稳定的形态和更好的器件性能。所有这些结果表明，利用烷基链间相互作用是控制形态演变的一种有效且实用的策略。
