Phenazine-containing poly(phenylenevinylene): a new polymer with impressive field emission properties

Abstract

Phenazine-containing poly(phenylenevinylene) (P(PHN-PV)) was synthesized using Wittig-Horner polycondensation of the appropriately designed monomers viz. 5,10-dioctyl-5,10-dihydrophenazine-2,7-dicarbaldehyde and tetraethyl ((2,5-bis((2-ethylhexyl) oxy)-1,4 phenylene) bis(methylene)) bis(phosphonate). The design embraces the specific motivation of incorporating the nitrogen-containing heterocycle viz. .phenazine in poly(phenylenevinylene) backbone. P(PHN-PV) exhibited reversible redox properties. In the field emission measurements performed on the film of P(PHN-PV), the turn-on field was observed to be 1.93 V/μm for the current density of 10 μA/cm2. The maximum current density of ~4.87 mA/cm2 was achieved at the applied field of 3.84 V/μm. The emission current showed impressive stability for 6 h at a constant current of 1 μA (current density of about 20 μA/cm2). These results emphasize the role of phenazine heterocycle with lone pair of electrons on nitrogen in lowering the oxidation onset and in turn reduction of the turn-on voltage.