为了合理设计用于太阳能电池的多2,7-碳醇衍生物
Nicolas Blouin1, Alexandre Michaud, David Gendron
1Département de Chimie, Université Laval, Quebec City, Quebec, G1K 7P4, Canada.
Journal of the American Chemical Society
|December 22, 2007
概括
研究人员利用理论模型优化了用于太阳能电池的聚2,7-碳醇衍生物. 苏苏基合产生了低带隙共聚合物,计算和实验能量水平之间的相关性很好,实现3.6%的功率转换效率.
科学领域:
- 材料科学 材料科学 材料科学
- 有机电子 有机电子
- 聚合物化学 聚合物化学
背景情况:
- 开发高效的有机太阳能电池需要新的半导体聚合物.
- 由于其可调节的电子特性,聚2,7-碳醇衍生物是有前途的候选物.
研究的目的:
- 为增强太阳能电池性能合成和表征优化的多2,7-碳醇衍生物.
- 研究聚合物结构,能量水平和设备效率之间的关系.
主要方法:
- 在模型化合物上进行理论建模和DFT计算.
- 苏苏基合反应用于合成交替共聚合物.
- 聚合物性质的实验性表征 (HOMO,LUMO,带隙,分子量,孔移动性).
主要成果:
- 实现了低频段间隙交替的共聚物,理论和实验能量水平之间有良好的相关性.
- 确定了碳醇部分作为HOMO水平的关键和LUMO水平的电子吸收共纳体.
- 证明了显著的孔移动性 (1 x 10(-3) cm2 x V(-1) x s(-1)) 和功率转换效率 (PCE) 高达3.6%.
结论:
- 聚合物分子重量和组织对于太阳能电池的性能至关重要,除了能量水平.
- 对称的合理设计,低频段间隙的聚2,7-碳醇) 衍生物具有进一步提高效率的潜力.
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.
01:26Photochemical 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
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.