Characterization of the Polymer Energy Landscape in Polymer:Fullerene Bulk Heterojunctions with Pure and Mixed Phases

被引：195

作者：

Sweetnam, Sean ^{[1
]}

Graham, Kenneth R. ^{[1
,2
]}

Ndjawa, Guy O. Ngongang ^{[2
]}

Heumueller, Thomas ^{[1
]}

Bartelt, Jonathan A. ^{[1
]}

Burke, Timothy M. ^{[1
]}

Li, Wentao ^{[3
]}

You, Wei ^{[3
]}

Amassian, Aram ^{[2
]}

McGehee, Michael D. ^{[1
]}

机构：

[1] Stanford Univ, Dept Mat Sci & Engn, Stanford, CA 94305 USA

[2] KAUST, Phys Sci & Engn Div, Mat Sci & Engn Program, Thuwal 239556900, Saudi Arabia

[3] Univ N Carolina, Dept Chem, Chapel Hill, NC 27599 USA

来源：

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY | 2014年 / 136卷 / 40期

基金：

美国国家科学基金会;

关键词：

INTERFACIAL ELECTRONIC-STRUCTURE; ORGANIC PHOTOVOLTAIC DEVICES; CHARGE-CARRIER MOBILITY; SOLAR-CELLS; LEVEL ALIGNMENT; SEMICONDUCTING POLYMERS; MOLECULAR PACKING; CRYSTALLIZATION; MORPHOLOGY; SEPARATION;

D O I：

10.1021/ja505463r

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

Theoretical and experimental studies suggest that energetic offsets between the charge transport energy levels in different morphological phases of polymer:fullerene bulk heterojunctions may improve charge separation and reduce recombination in polymer solar cells (PSCs). In this work, we use cyclic voltammetry, UVvis absorption, and ultraviolet photoelectron spectroscopy to characterize hole energy levels in the polymer phases of polymer:fullerene bulk heterojunctions. We observe an energetic offset of up to 150 meV between amorphous and crystalline polymer due to bandgap widening associated primarily with changes in polymer conjugation length. We also observe an energetic offset of up to 350 meV associated with polymer:fullerene intermolecular interactions. The first effect has been widely observed, but the second effect is not always considered despite being larger in magnitude for some systems. These energy level shifts may play a major role in PSC performance and must be thoroughly characterized for a complete understanding of PSC function.

引用

页码：14078 / 14088

页数：11

共 50 条

[11] Orientation-dependent ionization energies and interface dipoles in ordered molecular assemblies [J].

Duhm, Steffen ;

Heimel, Georg ;

Salzmann, Ingo ;

Glowatzki, Hendrik ;

Johnson, Robert L. ;

Vollmer, Antje ;

Rabe, Juergen P. ;

Koch, Norbert .

NATURE MATERIALS, 2008, 7 (04) :326-332

[12] Experimental estimation of the electric dipole moment and polarizability of titanyl phthalocyanine using ultraviolet photoelectron spectroscopy [J].

Fukagawa, H ;

Yamane, H ;

Kera, S ;

Okudaira, KK ;

Ueno, N .

PHYSICAL REVIEW B, 2006, 73 (04)

[13] Spatially Resolving Ordered and Disordered Conformers and Photocurrent Generation in Intercalated Conjugated Polymer/Fullerene Blend Solar Cells [J].

Gao, Jian ;

Thomas, Alan K. ;

Johnson, Ryan ;

Guo, Hua ;

Grey, John K. .

CHEMISTRY OF MATERIALS, 2014, 26 (15) :4395-4404

[14] Suppression of geminate charge recombination in organic photovoltaic devices with a cascaded energy heterojunction [J].

Groves, Chris .

ENERGY & ENVIRONMENTAL SCIENCE, 2013, 6 (05) :1546-1551

[15] Electronic structure of the poly(3-hexylthiophene):indene-C60 bisadduct bulk heterojunction [J].

Guan, Ze-Lei ;

Kim, Jong Bok ;

Loo, Yueh-Lin ;

Kahn, Antoine .

JOURNAL OF APPLIED PHYSICS, 2011, 110 (04)

[16] Direct determination of the electronic structure of the poly(3-hexylthiophene):phenyl-[6,6]-C61 butyric acid methyl ester blend [J].

Guan, Ze-Lei ;

Kim, Jong Bok ;

Wang, He ;

Jaye, Cherno ;

Fischer, Daniel A. ;

Loo, Yueh-Lin ;

Kahn, Antoine .

ORGANIC ELECTRONICS, 2010, 11 (11) :1779-1785

[17] How the Charge-Neutrality Level of Interface States Controls Energy Level Alignment in Cathode Contacts of Organic Bulk-Heterojunction Solar Cells [J].

Guerrero, Antonio ;

Marchesi, Luis F. ;

Boix, Pablo P. ;

Ruiz-Raga, Sonia ;

Ripolles-Sanchis, Teresa ;

Garcia-Belmonte, Germa ;

Bisquert, Juan .

ACS NANO, 2012, 6 (04) :3453-3460

[18] Studying Polymer/Fullerene Intermixing and Miscibility in Laterally Patterned Films with X-Ray Spectromicroscopy [J].

He, Xiaoxi ;

Collins, Brian A. ;

Watts, Benjamin ;

Ade, Harald ;

McNeill, Christopher R. .

SMALL, 2012, 8 (12) :1920-1927

[19] Morphology of polymer/fullerene bulk heterojunction solar cells [J].

Hoppe, H ;

Sariciftci, NS .

JOURNAL OF MATERIALS CHEMISTRY, 2006, 16 (01) :45-61

[20] Photoelectron spectroscopic study of the electronic band structure of polyfluorene and fluorene-arylamine copolymers at interfaces [J].

Hwang, Jaehyung ;

Kim, Eung-Gun ;

Liu, Jie ;

Bredas, Jean-Luc ;

Duggal, Anil ;

Kahn, Antoine .

JOURNAL OF PHYSICAL CHEMISTRY C, 2007, 111 (03) :1378-1384

← 1 2 3 4 5 →