在具有高开放电路电压的有机光伏设备中进行电荷重组
Sebastian Westenhoff1, Ian A Howard, Justin M Hodgkiss
1OE-Group, Cavendish Laboratory, JJ Thomson Avenue, Cambridge CB3 0HE, UK. westenho@chem.gu.se
Journal of the American Chemical Society
|September 19, 2008
概括
在有机光伏设备中,紧密结合的电荷对重组成三重激子,限制性能. 这项研究揭示了在接口上的电荷不运动是有机太阳能电池效率的一个关键因素.
科学领域:
- 材料科学 材料科学 材料科学
- 物理化学 物理化学
- 有机电子 有机电子
背景情况:
- 有机光伏 (OPV) 设备由于其灵活性和低制造成本,为基于的太阳能电池提供了一个有希望的替代方案.
- 在OPV中高开通电路电压 (Voc) 对于高效的能量转换是可取的,但了解性能限制至关重要.
- 电荷重组路径显著影响OPV设备的整体效率.
研究的目的:
- 阐明有机光伏设备中具有高开放电路电压的详细电荷重组机制.
- 在二元混合多联聚合物基OPV中识别主要的性能限制过程.
- 为设计下一代有机光伏材料提供见解,以提高效率.
主要方法:
- 使用可见和红外探测器的光学暂时吸收 (TA) 光谱学.
- 实现了跨越七十年的高时间分辨率.
- 采用极化分辨率TA光谱学来追踪时间和空间中的极子状态运动.
主要成果:
- 确定了密切结合的电荷对的高效重组成中性三重激子作为性能限制过程.
- 证明了光生成的电荷对在异质连接处的显著不动性.
- 量化了75%的电荷对通过系统间交叉在大约40秒内分解为三重激子.
- 观察到三重激子形成可以在高Voc聚合物太阳能电池中热力学上获得.
结论:
- 在这些高Voc OPV中,占主导地位的损失机制是接口电荷对重组成三重激子.
- 系统间交叉和随后的三重激子形成对于没有经历长距离电荷分离的电荷对具有重要意义.
- 设计能够在40毫秒内促进电荷分离的OPV材料对于提高设备性能至关重要.
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