POWDERY PHOSPHOR AND PROCESS FOR PRODUCING THE SAME, AND LIGHT EMITTING DEVICE, DISPLAY DEVICE AND FLUORESCENT LAMP CONTAINING POWDERY PHOSPHOR

摘要

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.