Copper nanoparticle incorporated plasmonic organic bulk-heterojunction solar cells

Abstract

By embedding copper nanoparticles into poly(3,4-thylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) layers, the power conversion efficiency of organic bulk-heterojunction solar cell using poly(3-hexylthiophene) (P3HT) was increased from 3.58% to 3.96%, and that of the device based on poly[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b′]dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl]] (PTB7) was increased from 6.79% to 7.43%. The copper nanoparticles enhanced light harvesting efficiency because of their localized surface plasmon resonance effects. This improved short circuit current densities, the dominant reason for the improvement in performance. Our results indicate that copper nanoparticles are cost-effective plasmonic materials for organic bulk-heterojunction solar cells as compared with gold and silver nano-structures.