Pi-conjugated polymers By Saren Johnston Simple polymers are long chains of molecules, generally carbon with hydrogen on the sides, all attached to one another by single bonds. As you go down a chain, regardless of what is on either side, the bonds are all single bonds.
Simple polymers are all very insulating, and the most common one is polyethylene.
The energy of the electrons in both double and triple bonds is much higher than the energy of the electrons in single bonds. Virtually all pi-conjugated polymers are semiconductors. The emissive polymer layer is sandwiched between two dissimilar metals, serving as cathode and anode, on a glass substrate. The current injected from the cathode into the polymer takes the form of negatively charged particles, while the current injected from the anode consists of positively charged particles, which travel through the polymer until they encounter the negative particles. When the two meet, the recombination creates excited states called singlet or triplet excitrons.