四元协同新策略推进大面积有机光伏组件效率大幅提升

有机太阳能电池具有成本低、质量轻、结构功能可调以及可大面积柔性制备等诸多优点，具有广阔的发展前景，已经成为新能源领域重要的发展方向之一。其中，优化大面积有机光伏组件的制备工艺，是实现低成本有机光伏产业化的关键所在。因此，发展高效的大面积有机光伏组件具有重要的实际意义。

目前，富勒烯衍生物受体材料凭借较高的电子亲和性和电子迁移率，从而在有机光伏中得到了广泛的应用，但其固有的巨大能量损失和较弱的光子吸收限制了其进一步的应用。非富勒烯受体材料在可见区具有较强的吸收并且结构能级可调，但存在载流子迁移率较低的缺点。因此，取二者之长是提高有机光伏组件光伏性能的有效策略。

浙江大学杨旸教授与朱海明教授以及杭州纤纳光电组成的合作团队在Photonics Research 2021年第3期（Ziyan Jia, Zeng Chen, Xu Chen, Jizhong Yao, Buyi Yan, Rui Sheng, Haiming Zhu, Yang (Michael) Yang. 19.34 cm² large-area quaternary organic photovoltaic module with 12.36% certified efficiency[J]. Photonics Research, 2021, 9(3): 03000324）发表的工作中采用四元协同策略，制备出认证效率12.36 %的大面积（19.34 cm²）有机光伏组件。

大面积有机光伏组件的真实图像与J-V曲线

此项工作基于先进的二元PM6:Y6活性层组分，通过加入富勒烯受体PC₇₁BM和非富勒烯受体ITIC，合理构造四元共混体系，改善了活性层薄膜纤维形貌，优化了载流子传输过程，从而实现了有机光伏组件开路电压（V_OC）、短路电流（J_SC）与填充因子（FF）的协同提升。此外，大面积组件结构采用了激光雕刻工艺，将7个子电池串联，最终实现了13.25 %的转化效率（认证为12.36 %）。其中，光照面积达到19.34 cm²，几何填充系数达到95.5 %。

此外，该项工作还展示了大面积有机光伏组件为手机充电的演示实验。在普通室内LED灯光照明下，大面积有机光伏组件可以为手机持续充电，这显示了其具有巨大的商业化前景。

研究人员认为合理搭配的活性层组分以及高效的组件结构，促进了大面积有机光伏组件效率的提升。未来的工作将继续发展大面积有机光伏组件制备的新技术，优化光电转化过程，提高光伏组件效率，进一步推进大面积有机光伏组件的实际应用。

19.34 cm² large-area quaternary organic photovoltaic module with 12.36% certified efficiency

Organic solar cells (OSCs) have many advantages such as low cost, light weight, and flexibility. They have broad prospects and have become one of the most important directions in photovoltaic technologies. Large-area fabrication of organic photovoltaic modules (OPMs) is the key technique to realizing the commercialization of organic photovoltaics. Therefore, it has great practical significance to develop the high-performance large-area OPMs.

At present, the widely used fullerene derivative acceptors generally have high electron affinity and electron mobility, but the inherent huge energy losses and the weak photon-harvesting capacities of fullerenes limited their applications. Meanwhile, the non-fullerene acceptors (NFAs) usually have strong absorption in the near-infrared region (NIR), and their energy levels can be easily adjusted to match the donors, but the carrier mobility of the NFAs is relatively low. Therefore, the synergy of fullerene acceptors and NFAs is an effective strategy to improve the photovoltaic performance of OPMs.

The recent work led by Prof. Yang (Michael) Yang from Zhejiang University published in Photonics Research, 2021, Vol. 9, No. 3 (Ziyan Jia, Zeng Chen, Xu Chen, Jizhong Yao, Buyi Yan, Rui Sheng, Haiming Zhu, Yang (Michael) Yang. 19.34 cm² large-area quaternary organic photovoltaic module with 12.36% certified efficiency[J]. Photonics Research, 2021, 9(3): 03000324) adopted the quaternary blending strategy, realizing a high-performance large area (19.34 cm²) OPM with a certified efficiency of 12.36 %.

The photo and the corresponding J-V curve of the large-area OPMs

In this work, the fullerene acceptor PC₇₁BM and the NFA ITIC were added in the binary PM6:Y6 components to construct a quaternary blending system. The morphology of the active layer films and the process of charge transfer were optimized, thereby promoting the synergistic improvement of the open-circuit voltage (V_OC), the short-circuit current-density (J_SC) and the fill factor (FF) of the OPMs. In addition, laser engraving was used in the monolithic module to connect seven sub-cells in series. Finally, an efficiency of 13.25 % (certified as 12.36 %) was achieved. Among them, the total illumination area is 19.34 cm², with geometrical filling factor of 95.5 %.

The large-area photovoltaic module was demonstrated to charge a cellphone under an indoor LED lamp, revealing its promising applications in the future. The researchers believe that the multicomponent blending strategy as well as the module manufacturing technique are the keys to realize efficient large-area OPMs. Future work will focus on the developing novel and effective manufacturing techniques for large-area OPMs, and optimizing the energy conversion processes in the modules.