Fluorine-doped tin oxide (FTO) electrodes have been investigated for u
se instead of indium-doped tin oxide (ITO) as the hole-injecting elect
rode in polymer light-emitting diodes (LEDs). The initial results pres
ented here lead to the conclusion that the electrode-polymer interface
is much more complex than a simple energy level diagram might imply.
Single-layer devices that differ only in the material of the electrode
(FTO or ITO) are compared, as are the effects of different methods of
cleaning the electrode material. PTO is shown to offer several advant
ages over ITO-including its cost.