An Optimal Driving Force for Converting Excitons into Free Carriers in Excitonic Solar Cells

被引：147

作者：

Coffey, David C. ^{[1
]}

Larson, Bryon W. ^{[2
]}

Hains, Alexander W. ^{[1
]}

Whitaker, James B. ^{[2
]}

Kopidakis, Nikos ^{[1
]}

Boltalina, Olga V. ^{[2
]}

Strauss, Steven H. ^{[2
]}

Rumbles, Garry ^{[1
,3
]}

机构：

[1] Natl Renewable Energy Lab, Golden, CO 80401 USA

[2] Colorado State Univ, Dept Chem, Ft Collins, CO 80523 USA

[3] Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA

来源：

JOURNAL OF PHYSICAL CHEMISTRY C | 2012年 / 116卷 / 16期

基金：

美国国家科学基金会;

关键词：

INTERMOLECULAR ELECTRON-TRANSFER; OPEN-CIRCUIT VOLTAGE; CHARGE-CARRIERS; CONJUGATED POLYMERS; ENERGY; BLENDS; EFFICIENCY; MOBILITY; CHAINS; HOLES;

D O I：

10.1021/jp302275z

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：

A general but limiting characteristic in excitonic photovoltaics is that a portion of the incident photon energy appears necessary for converting excitons into electrical charges, resulting in a loss of efficiency. Currently, the mechanism underlying this process is unclear. Here, we describe the development of an experimental method for measuring charge creation yields in organic solar cell materials. We use this method to examine a series of conjugated polymer:fullerene blend films and observe two unexpected features: the existence of an optimal driving force and a loss in conversion efficiency if this force is exceeded. These observations have implications for the design of excitonic photovoltaic devices and can be explained by a simple Marcus formulation that introduces the importance of reorganization energy.

引用

页码：8916 / 8923

页数：8

共 44 条

[1] Comment on "Exothermic Rate Restrictions in Long-Range Photoinduced Charge Separations" [J].