第一作者:凌曌恒, 吴敬男
通讯作者:凌曌恒,王二刚,Thomas D. Anthopoulos
通讯单位:曼彻斯特大学
01引言
有机光伏(OPV) 正迅速成为一种有前途的可再生能源,其特点是具有许多吸引人的特性,包括良好的能量转换效率 (PCE)、可调的光学透明度以及通过溶液处理技术实现低成本制造的潜力。近年来,在提高小分子受体 (SMA) OPV 性能方面取得了重大进展,通过合成具有不同功能的新有机分子、优化薄膜形貌、利用创新的电荷传输层和设计器件架构,实现了超过20% 的 PCE。然而,高性能 SMA-OPV 往往缺乏长期稳定性和机械强度,主要是由于 SMA 分子在光照和热量下快速扩散导致共混物形态退化,而这源于其低玻璃化转变温度(Tg) 和高扩散系数。在之前的研究中,我们合成了一种二聚化受体 DIBP3F-Se,通过将 Y6 衍生物与硒吩桥单元连接并采用 O 形构象,通过端基 IC 基团之间强大的分子内 π-π 相互作用形成独特的“构象锁”,实现了超过 18% 的 PCE。尽管如此,这些二聚体的分子堆积相对较低,导致复合率高于基于 SMA 的OPV。
02成果展示
近期,阿卜杜拉国王科技大学/曼彻斯特大学Thomas D. Anthopoulos团队的凌曌恒(第一作者,通讯作者) 与 查尔莫斯理工大学吴敬男 (共一作者) 合成了非对称非富勒烯 SMA BTP-J17,并将其作为第三组分加入PM6:DIBP3F-Se 共混物中。发现 BTP-J17 扩散到宿主供体/受体界面,从而增强了电荷分离并提高了载流子迁移率。至关重要的是,BTP-J17通过促进 DIBP3F-Se 的均匀分布和增强分子堆积来减少能量损失,从而提高开路电压(VOC = 0.941V),同时保持高 JSC(26.7mAcm−2),从而使 OPV 的最大PCE 为 19.6%。将三元PM6:DIBP3F-Se:BTP-J17 (1:1:0.6 (wt%)) 混合物与乙基紫精 (EV) 进行 N 型掺杂并使用 MgF2 作为抗反射涂层,可将 PCE 提高到最大值 20.5%。随后研制的三元OPV表现出了增强的运行稳定性,在沙特阿拉伯炎热潮湿的环境下连续7周的户外测试后仍能保持其初始PCE的80%。
该论文以“20.5 % efficient ternary organic photovoltaics using an asymmetric small-molecular acceptor to manipulate intermolecular packing and reduce energy losses”为题发表在 Materials Science and Engineering: R: Reports(MSER)上。凌曌恒,王二刚和Thomas D. Anthopoulos为共同通讯作者, 凌曌恒,吴敬男为该论文第一作者。
03图文导读
Fig. 1. Structure and physical properties of the active materials used in this study. (a) Molecular structures of PM6, DIBP3F-Se, and BTP-J17. (b) The absorption spectra of the PM6, DIBP3F-Se, and BTP-J17 neat films. (c) Energy levels of PM6, DIBP3F-Se, and BTP-J17. (d) The corresponding IP and OOP profiles of DIBP3F-Se and BTP-J17 acceptor films. (e) The CCL and dπ-π values of the DIBP3F-Se and BTP-J17 acceptor films.
Fig. 2. Solar cell architecture and characterization. (a) Schematic structure of the cells developed in this study. (b) J-V characteristics of the different cells. (c) EQE spectra obtained from the corresponding OPVs. (d) TRPL decays of binary and ternary BHJ systems; J-V curves measured for electron-only (e) and hole-only (f) devices based on the binary and ternary BHJs. (g) TDCF measurements of PM6:DIBP3F-Se and PM6:DIBP3F-Se OPVs. (h) TDCF measurements of PM6:DIBP3F-Se and PM6:DIBP3F-Se:BTP-J17 OPVs. (i) TPV spectra of PM6:DIBP3F-Se and PM6:DIBP3F-Se:BTP-J17 OPVs.
Fig. 3. Morphological characterizations of different blend layers. (a)-(b) Top images: AFM Phase images of the relevant blends. (c)-(d) KPFM images of relevant blends. (e) Surface height distribution of relevant blends. (f) Surface potentials measured for the binary and ternary blends. (g)-(h) 2D GIWAXS patterns of the relevant BHJs. (i)-(j) IP and OOP extracted line-cut profiles for the two blend layers.
Fig. 4. Blend and device physics characterization. (a) TOF-SIMS for the BHJ films. (b) Depth-Profile XPS for the BHJ films. (c) The sEQE and EL spectra of PM6:DIBP3F-Se OPV. (d) The sEQE and EL spectra of PM6:DIBP3F-Se:BTP-J17 OPV. (e) EL quantum efficiencies of PM6:DIBP3F-Se based binary and PM6:DIBP3F-Se:BTP-J17 based ternary OPVs. (f) Schematic diagram for energy losses of the two types of OPVs.
Fig. 5. Stability analysis of binary and ternary BHJ-based OPVs. (a) Normalized PCE for the encapsulated cells measured at noontime every day. Inset: photographs depicting the actual devices used for the testing (left and right) and the outdoor experimental settings (middle). The outdoor stability analysis was carried out within the KAUST campus in Thuwal, Kingdom of Saudi Arabia, from April 18th to June 12th 2024. The average relative humidity during the testing period was ≈ 63 %. J–V curves were measured every 10 min during the daytime. (b) Solar irradiance measured during the test period. (c) Air temperature measured during the test period. Power generation density (PGD) of the encapsulated (d) PM6:DIBP3F-Se and (e) PM6:DIBP3F-Se:BTP-J17 cells, respectively.
小结
总之,我们设计并合成了一种非对称 SMA,名为 BTP-J17,并将其用作基于 PM6:DIBP3F-Se 的 OPV 中的第三个组分。与 DIBP3F-Se 相比,BTP-J17 表现出蓝移吸收光谱,当两种组分混合时,随后的层表现出增强的吸收系数。实验研究表明,BTP-J17 扩散到 PM6/DIBP3F-Se 界面,改善激子分离并增强载流子传输,同时稳定 BHJ 的形态。至关重要的是,激子动力学研究表明,以最佳浓度添加 BTP-J17 可抑制复合损失。这些有利特性使得 OPV 的开发成为可能,其 PCE 高达 19.60%。通过加入 100 nm 厚的 MgF2 作为抗反射层,并使用分子掺杂剂乙基紫精对三元PM6:DIBP3F-Se:BTP-J17 BHJ 进行 n 掺杂,电池的最大 PCE进一步提高到 20.5% (JSC= 27.85 mA cm−2、VOC = 0.942 V、FF = 78.35%)。除了卓越的性能外,优化的三元 BHJ 电池在沙特阿拉伯的户外测试中表现出更好的运行稳定性,T80 时间为七周。本研究为非对称 SMA 如何帮助提高 OPV 的性能提供了新的见解,并强调了一种提高最先进 OPV 整体性能的有前途的策略。
文章信息
20.5 % efficient ternary organic photovoltaics using an asymmetric small-molecular acceptor to manipulate intermolecular packing and reduce energy losses
Zhaoheng Ling*, Jingnan Wu, José P. Jurado a, Christopher E. Petoukhoff, Sang Young Jeong, Dipti Naphade, Maxime Babics, Xiaoming Chang, Hendrik Faber, Spyros Doukas, Elefterios Lidorikis, Mohamad Insan Nugraha, Mingjie He, Maryam Alqurashi, Yuanbao Lin, Xiaokang Sun, Hanlin Hu, Han Young Woo, Stefaan De Wolf, Leonidas Tsetseris, Frédéric Laquai, Donghong Yu, Ergang Wang*, Thomas D. Anthopoulos*
Materials Science & Engineering R 163 (2025) 100922
https://doi.org/10.1016/j.mser.2024.100922