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Oxide Sandwiched Metal Thin‐Film Electrodes for Long‐Term Stable Organic Solar Cells
Author(s) -
Schubert Sylvio,
Hermenau Martin,
Meiss Jan,
MüllerMeskamp Lars,
Leo Karl
Publication year - 2012
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.201201592
Subject(s) - materials science , oxide , electrode , photocurrent , organic solar cell , layer (electronics) , solar cell , chemical engineering , metal , silver oxide , energy conversion efficiency , inorganic chemistry , optoelectronics , nanotechnology , composite material , metallurgy , chemistry , engineering , polymer
Oxide/silver/oxide multilayers as semitransparent top electrode for small molecule organic solar cells (OSCs) are presented. It is shown that two oxide layers sandwiching a central metal layer greatly improve the stability and lifetime of the organic solar cell. Thermally evaporated MoO 3 , WO 3 , or V 2 O 5 layers are employed as an interlayer for subsequent silver deposition and significantly change the morphology of the ultrathin silver layer, improving charge extraction and electrodes series resistance. The transmittance of the electrode is increased by introducing oxide or oxide and organic multilayers as capping layer, which leads to higher photocurrent generation in the absorber layer. Application of 1 nm MoO 3 /11 nm Ag/10 nm MoO 3 /50 nm Alq 3 multilayer electrodes in OSCs lead to an efficiency of 2.6% for a standard ZnPc:C60 cell, showing superior performance compared to devices with pure silver top contacts. The device lifetime is also strongly increased. MoO 3 layers can saturate and stabilize the inner and outer metal surface, passivating it against most of the degradation mechanisms. With such an oxide/silver/oxide multilayer electrode, the time until the glass encapsulated OSC is degraded to 80% of its starting efficiency is enhanced from 86 h to approximately 4500 h compared to an OSC without an oxide interlayer.