Layer-by-layer graphene/TCNQ stacked films as conducting anodes for organic solar cells.
Large-area graphene grown by chemical vapor deposition (CVD) is a promising candidate for transparent conducting electrode applications in flexible optoelectronic devices such as light-emitting diodes or organic solar cells. However, the power conversion efficiency (PCE) of the polymer photovoltaic devices using a pristine CVD graphene anode is still not appealing due to its much lower conductivity than that of conventional indium tin oxide. We report a layer-by-layer molecular doping process on graphene for forming sandwiched graphene/tetracyanoquinodimethane (TCNQ)/graphene stacked films for polymer solar cell anodes, where the TCNQ molecules (as p-dopants) were securely embedded between two graphene layers. Poly(3-hexylthiophene)/phenyl-C61-butyric acid methyl ester (P3HT/PCBM) bulk heterojunction polymer solar cells based on these multilayered graphene/TCNQ anodes are fabricated and characterized. The P3HT/PCBM device with an anode structure composed of two TCNQ layers sandwiched by three CVD graphene layers shows optimum PCE (∼2.58%), which makes the proposed anode film quite attractive for next-generation flexible devices demanding high conductivity and transparency.
Department of Material Science and Engineering, National Chiao Tung University, Hsinchu 300, Taiwan.
Chang-Lung
CL
Hsu
Cheng-Te
CT
Lin
Jen-Hsien
JH
Huang
Chih-Wei
CW
Chu
Kung-Hwa
KH
Wei
Lain-Jong
LJ
Li
D004553:Electric Conductivity; D011211:Electric Power Supplies; D004566:Electrodes; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006108:Graphite / Q000737:chemistry*; D008567:Membranes, Artificial; D009570:Nitriles / Q000737:chemistry*; D012993:Solar Energy
D008567:Membranes, Artificial; D009570:Nitriles; C013703:tetracyanoquinodimethane; D006108:Graphite