Effect of Crystallization on the Electronic Energy Levels and Thin Film Morphology of P3HT:PCBM Blends
Effect of Crystallization on the Electronic Energy Levels and Thin Film Morphology of P3HT:PCBM Blends
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DOI：
10.1021/ma102841e
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发表时间：
2011-04-26
期刊：
影响因子：
5.5
通讯作者：
Kim, Ji-Seon
中科院分区：
文献类型：
--
作者：
Tsoi, Wing C.;Spencer, Steve J.;Kim, Ji-Seon
研究了半结晶区域规则聚（3-己基噻吩）（RR-P3 HT）和非晶区域无规聚（3-己基噻吩）（RRa-P3 HT）与[6，6]-苯基C-61丁酸甲酯（PCBM）共混物的薄膜。紫外和（角分辨）X射线光电子能谱技术与吸收，光致发光和光学显微镜一起被用来测量这些薄膜的电子能级，垂直化学成分和光学性质。我们发现，有序的P3 HT链提高了最高占据分子轨道（HOMO）的能级的P3 HT薄膜（降低电离势）和P3 HT链的有序优先发生在RR-P3 HT：PCBM薄膜中的膜-空气界面。这导致P3 HT和PCBM分子之间的垂直相分离，这对于常规P3 HT：PCBM太阳能电池可能是不期望的。
We study thin films of semi-crystalline regioregular poly(3-hexylthiophene) (RR-P3HT) and amorphous regiorandom P3HT (RRa-P3HT) in blends with [6,6]-phenyl C-61 butyric acid methyl ester (PCBM). Ultraviolet and (angle-resolved) X-ray photoelectron spectroscopy techniques together with absorption, photoluminescence and optical microscopy were used to measure electronic energy levels, vertical chemical compositions and optical properties of these films. We find that ordering the P3HT chains raises the highest occupied molecular orbital (HOMO) energy level of P3HT thin films (reducing ionization potential) and that the ordering of P3HT chains occurs preferentially at the film-air interface in RR-P3HT:PCBM thin films. This leads to a vertical phase separation between P3HT and PCBM molecules, which may be undesirable for conventional P3HT:PCBM solar cells.