Fluorescent powder, process for producing the same, and light emitting device, display device, and fluorescent lamp containing fluorescent powder

Abstract

According to the present invention, a fluorescent powder composed mainly of an acicular or fibrous zinc oxide single crystal with an aspect ratio of 5 or higher is produced by the following steps: a step of producing a raw material solution selected from the group consisting of a raw material solution (A) that is an alkali solution containing zing ions, a raw material solution (B) that is a solution containing zinc ions and ions of dopant element, and a mixed solution of the raw material solution (A) and the raw material solution (B); and a hydrothermal reaction step wherein a hydrothermal reaction of the mixed solution is carried out in a hermetically sealed vessel at a subcritical or supercritical temperature and at a subcritical or supercritical pressure. A zinc oxide single crystal powder can be produced at low cost without the need for a pulverization step or a similar step and high-density orientation can be realized by such crystal powder. Such crystal powder is most suitable for light emitting devices, display devices, fluorescent lamps, and the like.

Dependencies are inferred from the claim text.