Visualizing charge separation in bulk heterojunction organic solar cells

被引：164

作者：

Vithanage, D. Amarasinghe ^{[1
]}

Devizis, A. ^{[2
]}

Abramavicius, V. ^{[2
,3
]}

Infahsaeng, Y. ^{[1
]}

Abramavicius, D. ^{[3
,4
]}

MacKenzie, R. C. I. ^{[5
,6
]}

Keivanidis, P. E. ^{[7
]}

Yartsev, A. ^{[1
]}

Hertel, D. ^{[8
]}

Nelson, J. ^{[5
,9
]}

Sundstrom, V. ^{[1
]}

Gulbinas, V. ^{[2
,10
]}

机构：

[1] Lund Univ, S-22100 Lund, Sweden

[2] Ctr Phys Sci & Technol, LT-02300 Vilnius, Lithuania

[3] Vilnius Univ, Dept Theoret Phys, LT-10222 Vilnius, Lithuania

[4] Jilin Univ, State Key Lab Supramol Struct & Mat, Changchun 130012, Peoples R China

[5] Univ Freiburg, Sch Soft Matter Res, FRIAS, D-1979104 Freiburg, Germany

[6] Univ Nottingham, Fac Engn, Dept Mech Mat & Mfg Engn, Nottingham NG7 2RD, England

[7] Ist Italiano Tecnol, Ctr Nano Sci & Technol PoliMi, I-20133 Milan, Italy

[8] Univ Cologne, Dept Chem, D-50939 Cologne, Germany

[9] Univ London Imperial Coll Sci Technol & Med, Ctr Plast Elect, Dept Phys, London SW7 2AZ, England

[10] Vilnius Univ, Dept Gen Phys & Spect, LT-10222 Vilnius, Lithuania

来源：

NATURE COMMUNICATIONS | 2013年 / 4卷

基金：

欧洲研究理事会;

关键词：

PHOTOVOLTAIC CELLS; EXCITON DISSOCIATION; ENERGY; PHOTOGENERATION; GENERATION; DEPENDENCE; MORPHOLOGY; STATE;

D O I：

10.1038/ncomms3334

中图分类号：

O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];

学科分类号：

07 ; 0710 ; 09 ;

摘要：

Solar cells based on conjugated polymer and fullerene blends have been developed as a low-cost alternative to silicon. For efficient solar cells, electron-hole pairs must separate into free mobile charges that can be extracted in high yield. We still lack good understanding of how, why and when carriers separate against the Coulomb attraction. Here we visualize the charge separation process in bulk heterojunction solar cells by directly measuring charge carrier drift in a polymer: fullerene blend with ultrafast time resolution. We show that initially only closely separated (<1 nm) charge pairs are created and they separate by several nanometres during the first several picoseconds. Charge pairs overcome Coulomb attraction and form free carriers on a subnanosecond time scale. Numerical simulations complementing the experimental data show that fast three-dimensional charge diffusion within an energetically disordered medium, increasing the entropy of the system, is sufficient to drive the charge separation process.

引用

页数：6

共 39 条

[31] Separation of geminate charge-pairs at donor-acceptor interfaces in disordered solids [J].