Blueshifting the Absorption of a Small -Molecule Donor and Using it as the Third Component to Achieve High-Efficiency Ternary Organic Solar Cells
Blueshifting the Absorption of a Small -Molecule Donor and Using it as the Third Component to Achieve High-Efficiency Ternary Organic Solar Cells
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DOI：
10.1002/solr.202200386
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发表时间：
2022-07-01
期刊：
影响因子：
7.9
通讯作者：
Yan, He
中科院分区：
文献类型：
--
作者：
Qi, Zhenyu;Yu, Han;Yan, He
向最先进的非富勒烯有机太阳能电池（OSC）中添加小分子供体（SMD）被证明是构建三元有机太阳能电池的有用策略，因为SMD通常具有高结晶度并且可以调节OSC的电荷传输特性。然而，大多数SMD的吸收与典型的供体聚合物（例如，PM 6），这违背了在三元OSC中采用具有互补吸收的材料的一般准则。在本文中，通过将外部噻吩的β位连接到内部噻吩单元的α位来吸收现有技术SMD（BTR-CI）是有意蓝移的。所得分子β-S1在膜状态下在505 nm处显示出最大吸收峰，其表现出较宽的带隙，并显示出与主体系统（PM 6：Y 6）的互补吸收。由于短路电流（J（sc））增加和填充因子（FF）改善，具有20%wt β-S1的相应三元OSC显示出从16.2%至17.1%的显著提高的效率。在此，提出了一种有效的策略来设计具有更宽的带隙和更高的结晶度的高性能三元OSC的SMD。
Adding a small-molecule donor (SMD) to state-of-the-art nonfullerene organic solar cells (OSCs) is demonstrated as a useful strategy to construct ternary organic solar cells, as SMDs typically have high crystallinity and can tune charge transport properties of OSCs. However, the absorption of most SMDs overlaps with typical donor polymers (e.g., PM6), which is against the general guidelines of adopting materials with complementary absorption in ternary OSCs. Herein, the absorption of state-of-art SMDs (BTR-CI) by linking the beta position of the outer thiophene to the alpha position of the inner thiophene unit is intentionally blueshifted. The resulting molecule beta-S1 shows a maximum absorption peak at 505 nm in the film state, which exhibits wider bandgap and shows complementary absorption with the host system (PM6:Y6). The corresponding ternary OSCs with 20%wt beta-S1 show significantly enhanced efficiency from 16.2% to 17.1% due to the increased short-circuit current (J(sc)) and improved fill factor (FF). Herein, an effective strategy to design SMDs with both wider bandgaps and higher crystallinity for high-performance ternary OSCs is presented.