Evidence of Delocalization in Charge-Transfer State Manifold for Donor:Acceptor Organic Photovoltaics

被引：13

作者：

Guan, Zhiqiang ^{[1
,2
]}

Li, Ho-Wa ^{[2
]}

Zhang, Jinfeng ^{[1
,2
]}

Cheng, Yuanhang ^{[2
]}

Yang, Qingdan ^{[1
,2
]}

Lo, Ming-Fai ^{[1
,2
]}

Ng, Tsz-Wai ^{[1
,2
]}

Tsang, Sai-Wing ^{[2
]}

Lee, Chun-Sing ^{[1
,2
]}

机构：

[1] City Univ Hong Kong, Ctr Super Diamond & Adv Films COSDAF, Hong Kong, Hong Kong, Peoples R China

[2] City Univ Hong Kong, Dept Phys & Mat Sci, Hong Kong, Hong Kong, Peoples R China

来源：

ACS APPLIED MATERIALS & INTERFACES | 2016年 / 8卷 / 33期

关键词：

delocalization; charge-transfer states; polaron states; charge-modulated electroabsorption spectroscopy; organic photovoltaics; HETEROJUNCTION SOLAR-CELLS; HOT EXCITON DISSOCIATION; QUANTUM EFFICIENCY; ELECTROABSORPTION; SEMICONDUCTOR; SEPARATION; POLYMER; SPECTROSCOPY; ACCEPTOR; ENERGY;

D O I：

10.1021/acsami.6b06010

中图分类号：

TB3 [工程材料学];

学科分类号：

0805 ; 080502 ;

摘要：

How charge-transfer states (CTSs) assist charge separation of a Coulombically bound exciton in organic photovoltaics has been a hot topic. It is believed that the delocalization feature of a CTS plays a crucial role in the charge separation process. However, the delocalization of the "hot" and the "relaxed" CTSs is still under debate. Here, with a novel frequency dependent charge-modulated electroabsorption spectroscopy (CMEAS) technique, we elucidate clearly that both "hot" and "relaxed" CTSs are loosely bound and delocalized states. This is confirmed by comparing the CMEAS results of CTSs with those of localized polaron states. Our results reveal the role of CTS delocalization on charge separation and indicate that no substantial delocalization gradient exists in CTSs.

引用

页码：21798 / 21805

页数：8

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