title: Au@Ag core-shell nanocubes for efficient plasmonic light scattering effect in low bandgap organic solar cells.
abstract: In this report, we propose a metal-metal core-shell nanocube (NC) as an advanced plasmonic material for highly efficient organic solar cells (OSCs). We covered an Au core with a thin Ag shell as a scattering enhancer to build Au@Ag NCs, which showed stronger scattering efficiency than Au nanoparticles (AuNPs) throughout the visible range. Highly efficient plasmonic organic solar cells were fabricated by embedding Au@Ag NCs into an anodic buffer layer, poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), and the power conversion efficiency was enhanced to 6.3% from 5.3% in poly[N-9-hepta-decanyl-2,7-carbazole-alt-5,5-(4,7-di-2-thienyl-2,1,3-benzothiadiazole)] (PCDTBT):[6,6]-phenyl C71-butyric acid methyl ester (PC70BM) based OSCs and 9.2% from 7.9% in polythieno[3,4-b]thiophene/benzodithiophene (PTB7):PC70BM based OSCs. The Au@Ag NC plasmonic PCDTBT:PC70BM-based organic solar cells showed 2.2-fold higher external quantum efficiency enhancement compared to AuNPs devices at a wavelength of 450-700 nm due to the amplified plasmonic scattering effect. Finally, we proved the strongly enhanced plasmonic scattering efficiency of Au@Ag NCs embedded in organic solar cells via theoretical calculations and detailed optical measurements.
authors.affiliation: Graduate School of Energy, Environment, Water, and Sustainability (EEWS), Graphene Research Center, Korea Advanced Institute of Science and Technology (KAIST) , Daejeon 305-701, Republic of Korea.
authors.forename: Se-Woong
authors.initials: SW
authors.lastname: Baek
authors.forename: Garam
authors.initials: G
authors.lastname: Park
authors.forename: Jonghyeon
authors.initials: J
authors.lastname: Noh
authors.forename: Changsoon
authors.initials: C
authors.lastname: Cho
authors.forename: Chun-Ho
authors.initials: CH
authors.lastname: Lee
authors.forename: Min-Kyo
authors.initials: MK
authors.lastname: Seo
authors.forename: Hyunjoon
authors.initials: H
authors.lastname: Song
authors.forename: Jung-Yong
authors.initials: JY
authors.lastname: Lee