1 research outputs found
Recycling Indium Tin Oxide (ITO) Electrodes Used in Thin-Film Devices with Adjacent Hole-Transport Layers of Metal Oxides
Many thin-film optoelectronic devices
use electrodes made of tin-doped
indium oxide (ITO), which is acceptably conductive, as well as virtually
transparent and colorless. Regrettably, indium is an uncommon element
and its price continues to rise, so it is increasingly important to
recover ITO electrodes from devices that are no longer needed. Previous
work has shown that simple sonication in neutral water can separate
intact ITO electrodes from other components in typical devices, in
which the active components and ITO are separated by an ionic buffer
layer of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS).
Sonication in water appears to be effective because it favors selective
penetration and dissolution of PEDOT:PSS, thereby freeing the underlying
ITO electrode. However, PEDOT:PSS is being replaced in emerging devices
by the use of various metal oxides as hole-transport materials. We
have now found that ITO electrodes in these new devices can be recycled
by sonication in dilute aqueous base. The layers of ITO undergo only
minor changes in composition and morphology, and the recovered electrodes
can be reused many times to fabricate new devices without loss of
performance