Source for thermal physical vapor deposition of organic electroluminescent layers

Abstract

A thermal physical vapor deposition electroluminescent source includes a housing defining an enclosure having side walls and a bottom wall, the enclosure receiving solid organic electroluminescent material which can be vaporized, and the width of the housing having a dimension w,; and the housing has a conductive portion defining a vapor efflux aperture slit having a width w,for permitting vaporized electroluminescent materials to pass through the slit onto a surface of a substrate. A conductive baffle member has width b, the baffle member being centered on the slit and spaced from the side walls and spaced from the top plate by a distance m, the baffle member substantially providing a line-of-sight covering of the slit preventing direct access of vaporized electroluminescent materials to the slit, and preventing particulate electroluminescent materials from passing through the slit; and a straight-line projection from an edge of the slit to an edge of the baffle member onto a side wall defining a position on the side wall such that such position is spaced from the top plate by a dimension L. The ratio of the dimensions w,to w,is in a range of from 1.5 to 6.0; the ratio of L to w,is in a range of from 2 to 6; and the ratio of m to L is in a range of from 0.15 to 0.40. Heat is applied to different parts of the housing to cause vapor deposition.