This invention is directed to phosphor particles and to field emission displays using the particles, each of the particles is coated with an electrically conducting material to impart to the particles environmental stability, stability under use conditions, and reduced charging. The housing has a first opening adapted to permit ionic communication between the first gel matrix and an external ionic buffer solution, and a second opening adapted to permit ionic communication between the second gel matrix and an external ionic buffer solution. The vial preferably includes at least one marker ring positioned between the first and second materials. The engaging portion has a bottom section and a top section. The setting of the counter electrode and the source line to the third potential occurs in a period of one frame.