Correlating the Hybridization of Local-Exciton and Charge-Transfer States with Charge Generation in Organic Solar Cells

被引：25

作者：

Qian, Deping ^{[1
,2
,3
,4
]}

Pratik, Saied Md ^{[5
]}

Liu, Qi ^{[6
]}

Dong, Yifan ^{[3
,4
]}

Zhang, Rui ^{[7
]}

Yu, Jianwei ^{[7
]}

Gasparini, Nicola ^{[3
,4
]}

Wu, Jiaying ^{[3
,4
]}

Zhang, Tiankai ^{[7
]}

Coropceanu, Veaceslav ^{[5
]}

Guo, Xia ^{[6
]}

Zhang, Maojie ^{[6
]}

Bredas, Jean-Luc ^{[5
]}

Gao, Feng ^{[7
]}

Durrant, James R. ^{[3
,4
,8
]}

机构：

[1] Fujian Normal Univ, Straits Inst Flexible Elect SIFE, Future Technol, Fuzhou 350117, Fujian, Peoples R China

[2] Straits Lab Flexible Elect SLoFE, Fuzhou 350117, Fujian, Peoples R China

[3] Imperial Coll London, Dept Chem, London W12 0BZ, England

[4] Imperial Coll London, Ctr Processable Elect, London W12 0BZ, England

[5] Univ Arizona, Dept Chem & Biochem, Tucson, AZ 85721 USA

[6] Shandong Univ, Natl Engn Res Ctr Colloidal Mat, Sch Chem & Chem Engn, Jinan 250100, Shandong, Peoples R China

[7] Linkoping Univ, Dept Phys Chem & Biol IFM, S-58183 Linkoping, Sweden

[8] Swansea Univ, Dept Mat Sci & Engn, Swansea SA1 8EN, Wales

来源：

ADVANCED ENERGY MATERIALS | 2023年 / 13卷 / 32期

基金：

中国国家自然科学基金; 瑞典研究理事会; 英国工程与自然科学研究理事会;

关键词：

charge generation; hybridization; non-radiative voltage loss; organic solar cells; EFFICIENCY; POLYMER; LOSSES;

D O I：

10.1002/aenm.202301026

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

In organic solar cells with very small energetic-offset (& UDelta;ELE - CT), the charge-transfer (CT) and local-exciton (LE) states strongly interact via electronic hybridization and thermal population effects, suppressing the non-radiative recombination. Here, we investigated the impact of these effects on charge generation and recombination. In the blends of PTO2:C8IC and PTO2:Y6 with very small, ultra-fast CT state formation was observed, and assigned to direct photoexcitation resulting from strong hybridization of the LE and CT states (i.e., LE-CT intermixed states). These states in turn accelerate the recombination of both CT and charge separated (CS) states. Moreover, they can be significantly weakened by an external-electric field, which enhanced the yield of CT and CS states but attenuated the emission of the device. This study highlights that excessive LE-CT hybridization due to very low , whilst enabling direct and ultrafast charge transfer and increasing the proportion of radiative versus non-radiative recombination rates, comes at the expense of accelerating recombination losses competing with exciton-to-charge conversion process, resulting in a loss of photocurrent generation.

引用

页数：9

共 46 条

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