Protection layer for a light emitting diode

Abstract

A particle layer is positioned over a light output surface of a light emitting diode. A transparent protection layer positioned between and in contact with the light output surface and the particle layer. The particle layer comprises a multitude of optically scattering or luminescent particles and a thin coating layer of transparent material coating particles of the multitude. The particles are characterized by a D50 greater than about 1.0 μm and less than about 30. μm; the coating layer has a thickness less than about 0.20 μm. The protection layer is less than about 0.05 μm thick and includes one or more materials different from material of the coating layer. The protection and coating layers can each include one or more metal or semiconductor oxides. Oxide precursor reactivities, with respect to the corresponding light output surface, are less for protection layer material than for coating layer material.

Dependencies are inferred from the claim text.