高效的无烯有机太阳能电池在接近零的最高占成的分子轨道偏移下运行
Shuixing Li1, Lingling Zhan1, Chenkai Sun2
1MOE Key Laboratory of Macromolecular Synthesis and Functionalization, State Key Laboratory of Silicon Materials, Department of Polymer Science and Engineering , Zhejiang University , Hangzhou 310027 , P.R. China.
Journal of the American Chemical Society
|January 29, 2019
概括
高性能有机太阳能电池 (OSC) 可以通过接近零的最高占用分子轨道 (HOMO) 偏移来实现. 这项研究揭示了电荷转移动态,并确定了双分子重组作为无烯OSC的关键性能限制.
科学领域:
- 材料科学
- 有机电子
- 太阳能发电
背景情况:
- 有机太阳能电池 (OSC) 是传统光伏的有希望的替代品.
- 目前正在探索无富勒烯的捐赠者:接受者 (D:A) 混合物,以提高OSC的稳定性和性能.
- 了解能量水平对齐的作用,特别是最高占成的分子轨道 (HOMO) 偏移,对于优化电荷传输和设备效率至关重要.
研究的目的:
- 研究不同HOMO偏移对无烯OSC电荷转移动态的影响.
- 建立基于设备特征的预测孔移动趋势的方法.
- 确定限制高效性OSC的关键因素.
主要方法:
- 用于评估孔移动的双层孔设备的制造和表征.
- 测量短暂的吸收光谱以研究超快速的电荷转移动态.
- 在不同的光强度下分析有机太阳能电池设备的参数.
主要成果:
- 只有双孔装置的不对称性与有机太阳能电池填充系数 (FF) 和短路电流密度 (Jsc) 相对应.
- 对于HOMO偏移≥0 eV,孔移超快 (≤4.6 ps),但对于负偏移显著减慢 (∼400 ps).
- 高功率转换效率 (PCE) 达到10.42%和11.75%,HOMO偏移接近零 (0和0.06 eV).
结论:
- 高性能无烯OSC可以在接近零的HOMO偏移下有效运行.
- 对正值的电荷转移动态在很大程度上独立于HOMO偏移,但对负值的偏移非常敏感.
- 双分子重组被认为是实现更高OSC性能的主要限制.
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