Department of Physics
Contrary interfacial exciton dissociation at metal/organic interface in regular and reverse configuration organic solar cells
© 2014 AIP Publishing LLC. An opposite interfacial exciton dissociation behavior at the metal (Al)/organic cathode interface in regular and inverted organic solar cells (OSCs) was analyzed using transient photocurrent measurements. It is found that Al/organic contact in regular OSCs, made with the blend layer of 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):3′H-Cyclopropa [8,25][5,6] fullerene-C70-D5h(6)-3′-butanoicacid,3′-phenyl-,methyl ester (PC70BM), always hampers the electron collection. However, this is not observed in their reverse geometry OSCs fabricated using the same PTB7:PC70BM blend system. The detrimental interfacial exciton dissociation in regular OSCs originates the compensation of field drifted photo-generated electrons at Al/organic interface. The unfavorable interfacial exciton dissociation can be eliminated, e.g., by interposing a ZnO-based interlayer between Al and organic layer, attaining an efficient electron collection, thereby power conversion efficiency.
Source Publication Title
Applied Physics Letters
American Institute of Physics
Wu, Bo, Zhenghui Wu, Hoi Lam Tam, and Furong Zhu. "Contrary interfacial exciton dissociation at metal/organic interface in regular and reverse configuration organic solar cells." Applied Physics Letters 105.10 (2014): 103302.