Flexible Ag electrode for use in organic photovoltaics

High efficiency organic photovoltaic cells discussed in literature are normally restricted to devices fabricated on glass substrates. This is a consequence of the extreme brittleness and inflexibility of the commonly used transparent conductive oxide electrode, indium tin oxide (ITO). This shortcoming of ITO along with other concerns such as increasing scarcity of indium, migration of indium to organic layer, etc. makes it imperative to move away from ITO. Here we demonstrate a highly flexible Ag electrode that possesses low sheet resistances even in ultra-thin layers. It retains its conductivity under severe bending stresses where ITO fails completely. A P3HT:PCBM blend organic solar cell fabricated on this highly flexible electrode gives an efficiency of 2.3%.

Ag film possesses very low sheet resistance even in the ultra-thin layers and has a very smooth surface. Also it is extremely flexible and retains its conductivity under severe bending stress. Organic photovoltaic devices fabricated on Ag–PEN films showed better performance than devices fabricated using ITO–PET .Figure optionsDownload as PowerPoint slideHighlights
► Organic photovoltaic devices were fabricated on thin Ag electrodes deposited by thermal evaporation on PEN substrate.
► Device fabricated on Ag–PEN showed a higher efficiency than the device fabricated on ITO–PET.
► Ag electrodes are highly flexible and retain their conductivity under severe bending stress.