Abstract: A protective layer of a plasma display panel includes smoky magnesium oxide, the smoky magnesium oxide having single crystal magnesium oxide with a plurality of cavities therein.

Abstract: Provided are a protecting layer for a plasma display panel (PDP), a method of forming the same, and a PDP including the protecting layer. The protecting layer includes a magnesium oxide-containing layer having a surface to which magnesium oxide-containing particles having a magnesium vacancy-impurity center (VIC) are attached. The protecting layer is resistant to plasma ions and has excellent electron emission effects, and thus, a PDP including the protecting layer can be operated at low voltage with high discharge efficiency.

Abstract: A protecting layer is formed of a magnesium oxide layer and electron emission promoting material formed on the magnesium oxide layer. The electron emission promoting material may be patterned on the magnesium oxide layer, or may be sprayed and heat-treated on the surface of the magnesium oxide layer. The protecting layer exhibits excellent electron emission characteristics while not being substantially damaged by plasma ions, thereby improving the reliability of a PDP.

Abstract: The sintered magnesium oxide according to one embodiment has a density of less than 3.5 g/cm3 and an average grain size of about 3 to about 10 ?m. A MgO protective layer made from the sintered magnesium oxide reduces a discharge voltage of a plasma display panel, improves its response speed, and provides it with high-purity film quality.

Abstract: A material for preparing a protective layer for a PDP, which reduces discharge delay time, improves temperature dependency, and has enhanced ion strength; a method of preparing the same; a protective layer formed of the material; and a PDP including the protective layer. More particularly, a material for a protective layer that includes monocrystalline magnesium oxide doped with a rare earth element at an amount of 2.0×10?5?1.0×10?2 parts by weight per 1 part by weight of magnesium oxide (MgO), a method of preparing the monocrystalline magnesium oxide by crystallizing it at about 2,800° C., a protective layer formed of the same, and PDP including the protective layer.

Abstract: A sintered magnesium oxide has a density of 3.5 g/cm3 or more, and has a grain size that is more than or equal to thirty times the average particle diameter of magnesium oxide particles. An MgO protective layer made from the sintered magnesium oxide reduces a discharge voltage of a plasma display panel, improves response speed, and provides a high-purity film quality.