US Patent 7432656 Plasma display panel and method for manufacturing same

A plasma display panel in which a first substrate having a protective layer formed thereon opposes a second substrate across a discharge space, with the substrates being sealed around a perimeter thereof. At a surface of the protective layer, first and second materials of different electron emission properties are exposed to the discharge space, with at least one of the materials existing in a dispersed state. The first and second materials may be first and second crystals, and the second crystal may be dispersed throughout the first crystal.