中国物理B ›› 2007, Vol. 16 ›› Issue (7): 2136-2141.doi: 10.1088/1009-1963/16/7/057

• CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES • 上一篇    下一篇

Solvent and electric field dependence of the photocurrent generation in donor:acceptor blend system

周印华, 杨中锋, 吴伟才, 夏海建, 温善鹏, 田文晶   

  1. Key Laboratory for Supramolecular Structure and Materials of Ministry of Education, Jilin University, Changchun 130012, China
  • 收稿日期:2006-12-01 修回日期:2006-12-10 出版日期:2007-07-04 发布日期:2007-07-04
  • 基金资助:
    Project supported by the State Key Development Program for Basic Research of China (Grant No 2002CB613401), the National Natural Science Foundation of China (Grant Nos 20474023 and 50673035), the Program for Changjiang Scholars and Innovative Research Tea

Solvent and electric field dependence of the photocurrent generation in donor:acceptor blend system

Zhou Yin-Hua(周印华), Yang Zhong-Feng(杨中锋), Wu Wei-Cai(吴伟才), Xia Hai-Jian(夏海建), Wen Shan-Peng(温善鹏), and Tian Wen-Jing (田文晶)   

  1. Key Laboratory for Supramolecular Structure and Materials of Ministry of Education, Jilin University, Changchun 130012, China
  • Received:2006-12-01 Revised:2006-12-10 Online:2007-07-04 Published:2007-07-04
  • Supported by:
    Project supported by the State Key Development Program for Basic Research of China (Grant No 2002CB613401), the National Natural Science Foundation of China (Grant Nos 20474023 and 50673035), the Program for Changjiang Scholars and Innovative Research Tea

摘要: This paper reports that the blend films of poly (2-methoxy-5-(2'-ethyl-hexyloxy)-p-phenylene vinylene) (MEH-PPV) and N,N'-bis(1-ethylpropyl)-3,4: 9,10-perylene bis (tetracarboxyl diimide) (EP-PDI) with the weight ratio of 1:2.5 have been prepared by spin-coating from chloroform (CF) and chlorobenzene (CB) solutions respectively. The absorption spectra and the morphology of the blend films show that large crystal-like EP-PDI aggregates are formed in film prepared from CB solution, which corresponds to a new absorption shoulder near 590nm, while there is no shoulder around 590\,nm in the UV--Vis absorption spectra of the blend film from CF solution. The electric-field dependence spectra of the photocurrent generation quantum yield of the film from CB solution shows that at weak electric field the EP-PDI aggregates act as more efficient sensitizers, but at strong electric field the quantum yields become almost invariable over the entire spectral range no matter what the state of EP-PDI, monomer or aggregate. At strong electric field, the photocurrent generation yields of both films from CF and CB solution saturate and their yield spectra become spectrally similar, mentioning that at strong electric field the photoexcitons dissociate efficiently and the free charges are collected by the electrodes almost completely.

Abstract: This paper reports that the blend films of poly (2-methoxy-5-(2'-ethyl-hexyloxy)-p-phenylene vinylene) (MEH-PPV) and N,N'-bis(1-ethylpropyl)-3,4: 9,10-perylene bis (tetracarboxyl diimide) (EP-PDI) with the weight ratio of 1:2.5 have been prepared by spin-coating from chloroform (CF) and chlorobenzene (CB) solutions respectively. The absorption spectra and the morphology of the blend films show that large crystal-like EP-PDI aggregates are formed in film prepared from CB solution, which corresponds to a new absorption shoulder near 590nm, while there is no shoulder around 590\,nm in the UV--Vis absorption spectra of the blend film from CF solution. The electric-field dependence spectra of the photocurrent generation quantum yield of the film from CB solution shows that at weak electric field the EP-PDI aggregates act as more efficient sensitizers, but at strong electric field the quantum yields become almost invariable over the entire spectral range no matter what the state of EP-PDI, monomer or aggregate. At strong electric field, the photocurrent generation yields of both films from CF and CB solution saturate and their yield spectra become spectrally similar, mentioning that at strong electric field the photoexcitons dissociate efficiently and the free charges are collected by the electrodes almost completely.

Key words: solvent effect, morphology, electric field dependence, photocurrent generation

中图分类号:  (Photoconduction and photovoltaic effects)

  • 73.50.Pz
61.41.+e (Polymers, elastomers, and plastics) 68.55.-a (Thin film structure and morphology) 73.61.Ph (Polymers; organic compounds) 78.40.Me (Organic compounds and polymers) 78.66.Qn (Polymers; organic compounds)