聚3-基thiophene) 区域规律性对烯复合材料太阳能电池性能的影响
Claire H Woo1, Barry C Thompson, Bumjoon J Kim
1Department of Chemical Engineering, University of California, Berkeley, California 94720, USA.
Journal of the American Chemical Society
|November 13, 2008
概括
聚3-基thiophene中较低的区域规律性提高了聚合物-富勒烯太阳能电池的热稳定性,而不会牺牲效率. 这表明受控障碍可以改善聚合物太阳能电池设计.
科学领域:
- 材料科学 材料科学 材料科学
- 聚合物科学 聚合物科学
- 有机电子 有机电子
背景情况:
- 聚合物-富勒烯复合材料是有机太阳能电池的关键.
- 聚合物区域的规律性影响了形态学和性能.
- 了解区域规律性的影响对于设备优化至关重要.
研究的目的:
- 调查聚3-基thiophene) 区域规律性对聚合物-富勒烯太阳能电池性能的影响.
- 为了将区域规律性与热稳定性和电荷传输特性相关联.
- 建立太阳能电池中半晶结合聚合物的设计原则.
主要方法:
- 合成和描述具有不同区域规律性 (86%,90%,96%) 的聚3-基烯.
- 使用这些聚合物制造的聚合物富勒烯太阳能电池的制造和测试.
- 使用差分扫描热量计 (DSC) 分析热稳定性.
- 使用二维放牧发生率X射线散射 (2D-GIXS) 调查形态学.
- 通过空间电荷有限电流 (SCLC) 测量电荷载体移动性.
主要成果:
- 低区域规律性聚合物产生了具有优越热稳定的富勒烯复合材料.
- 增强的热稳定性与减少聚合物结晶的驱动力有关.
- 所有测试的区域规律性都实现了类似的太阳能电池峰值效率 (~4%).
- 在所有聚合物样本中,电荷载体的移动性是可比的 (10^-4 cm^2 V^-1 s^-1).
结论:
- 高的区域规律性对于高分子太阳能电池中有效的电荷传输是不必要的.
- 聚合物骨干中受控的障碍可以抑制结晶驱动的相分离.
- 这为改进的半晶联聚合物太阳能电池提供了设计策略.
相关概念视频
01:17Thermal Electrocyclic Reactions: Stereochemistry
The stereochemistry of electrocyclic reactions is strongly influenced by the orbital symmetry of the polyene HOMO. Under thermal conditions, the reaction proceeds via the ground-state HOMO.
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.
01:26Thermal and Photochemical Electrocyclic Reactions: Overview
Electrocyclic reactions are reversible reactions. They involve an intramolecular cyclization or ring-opening of a conjugated polyene. Shown below are two examples of electrocyclic reactions. In the first reaction, the formation of the cyclic product is favored. In contrast, in the second reaction, ring-opening is favored due to the high ring strain associated with cyclobutene formation.
01:26Photochemical Electrocyclic Reactions: Stereochemistry
The absorption of UV–visible light by conjugated systems causes the promotion of an electron from the ground state to the excited state. Consequently, photochemical electrocyclic reactions proceed via the excited-state HOMO rather than the ground-state HOMO. Since the ground- and excited-state HOMOs have different symmetries, the stereochemical outcome of electrocyclic reactions depends on the mode of activation; i.e., thermal or photochemical.
Selection Rules: Photochemical Activation
Selection Rules: Photochemical Activation