A plasma-addressed electro-optic display device comprising a layer of electro-optic material, data electrodes coupled to the electro-optic layer and adapted to receive data voltages for activating portions of the electro-optic layer, and a plurality of plasma channels extending generally transverse to the data electrodes for selectively switching on said electro-optic portions. The plama channels each comprise spaced elongated cathode and anode plasma electrodes and an ionizable gas filling. To improve performance, reliability and lifetime of the device, at least the cathode electrodes have surface portions comprised of a negative electron affinity material. Preferably, the negative electron affinity material is a film of conductive or semiconductive diamond, diamond-like carbon, or aluminum nitride.