Carrier generation and transport in bulk heterojunction films processed with 1,8-octanedithiol as a processing additive
Carrier generation and transport in bulk heterojunction films processed with 1,8-octanedithiol as a processing additive
复制标题
DOI：
10.1063/1.2951957
复制
发表时间：
2008-08
影响因子：
3.2
通讯作者：
I. Hwang;Shinuk Cho;J. Y. Kim;Kwanghee Lee;Nelson E. Coates;D. Moses;A. Heeger
中科院分区：
文献类型：
--
作者：
I. Hwang;Shinuk Cho;J. Y. Kim;Kwanghee Lee;Nelson E. Coates;D. Moses;A. Heeger
通过在用于旋转浇铸本体异质结膜的聚合物溶液中使用1，8-辛二硫醇（ODT）作为加工添加剂，获得了基于聚[2，6-（4，4-双-（2-乙基己基）-4H-环戊二烯并[2，1-B; 3，4-B′]二噻吩）-alt-4，7-（2，1，3-苯并噻二唑）] PCPDTBT的聚合物基太阳能电池的改进的性能。尽管超快光谱研究表明，在用ODT处理的膜中载流子损耗减少[类似于由P3 HT：PCBM制成的体异质结（BHJ）材料的热退火后载流子损耗减少]，但是减少的幅度不足以解释所观察到的功率转换效率增加2倍。从场效应晶体管中载流子输运的分析，我们发现增加的电子迁移率的PCPDTBT：PC 70 BM复合材料时，与ODT制造，这是增强的连接性的PC 70 BM网络的指示。改进的电子迁移率似乎是改进的功率转换的主要来源。
Improved performance of polymer-based solar cells based on poly[2,6-(4,4-bis-(2-ethylhexyl)-4H-cyclopenta[2,1-b;3,4-b′]dithiophene)-alt-4,7-(2,1,3-benzo-thiadiazole)] PCPDTBT has been obtained by using 1,8-octanedithiol (ODT) as a processing additive in the polymer solution used to spin cast the bulk heterojunction films. Although ultrafast spectroscopy studies indicate that the carrier losses are reduced in the films processed with ODT [similar to the reduced carrier losses after thermal annealing of bulk heterojunction (BHJ) materials made from P3HT:PCBM], the magnitude of the reduction is not sufficient to explain the observed factor of 2 increase in the power conversion efficiency. From the analysis of carrier transport in field effect transistors, we find increased electron mobility in the PCPDTBT:PC70BM composites when fabricated with ODT, which is indicative of enhanced connectivity of PC70BM networks. The improved electron mobility appears to be the primary origin of the improved power conversion ...