| 초록 |
We demonstrate highly efficient inverted polymer solar cells (PSCs) by replacing indium tin oxide (ITO) with poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) as cathodes with interfacial engineering. Demands of flexible energy generation devices create the architectures of ITO-free PSCs. However, oxidation of low work function (WF) metal electrodes leads negative influence to stability of PSCs. ITO-free PSCs in inverted structure which use high WF metals (e.g. Ag, Au) as anodes can be the solution. Polyethylenimine ethoxylated (PEIE) is well known as both WF modifier and electron selective layer. PEIE–modification is demanded to PEDOT:PSS electrodes because WF of PEDOT:PSS is not appropriate as cathodes in inverted PSCs, and it facilitates electron transfer to PEDOT:PSS electrodes. It allows long-term stability and high-performance of ITO-free PSCs in inverted structure with efficiency around 7.5%. |
