在多晶五中激电子裂变的超快动态
Mark W B Wilson1, Akshay Rao, Jenny Clark
1Cavendish Laboratory, University of Cambridge, J.J. Thomson Avenue, Cambridge CB3 0HE, UK.
Journal of the American Chemical Society
|July 16, 2011
概括
超快速光谱学揭示,五纪薄膜中的单个激子在80 fs内迅速转化为三重激子. 这种高效的刺激子裂变过程是通过多个刺激子产生来提高有机太阳能电池性能的关键.
科学领域:
- 光物理学的光学物理学
- 材料科学 材料科学 材料科学
- 有机电子 有机电子
背景情况:
- 刺激子裂变是一种过程,其中一个高能刺激子分裂成两个低能三重刺激子.
- 了解刺激子裂变的动力学对于开发高效的有机太阳能电池至关重要.
- 五烯是一种模型有机半导体,用于研究激子动力学.
研究的目的:
- 直接探测在五中刺激子裂变的超快动力学.
- 为了确定单个刺激子转化为三重刺激子的时间尺度和效率.
- 调查刺激裂变的机制和影响因素.
主要方法:
- 超快速的短暂吸收光谱,时间分辨率低于20 femtosecond (fs).
- 广泛的光谱覆盖,以监测激素种群.
- 取决于激发波长的测量.
主要成果:
- 绝大多数单个刺激子在大约80 fs的时间尺度上演变成三重刺激子.
- 刺激子裂变速率相当于通过声子介导的刺激子局部化.
- 刺激发射证实了最低的单个国家寿命极短,违反了卡沙的规则.
结论:
- 在太烯中激发裂变是一个快速而高效的过程.
- 这个过程很可能直接发生在最初的移位状态中.
- 通过激子裂变产生多个激子是提高有机太阳能电池效率的有希望的策略.
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