Improving optical separation of needle-like phosphor layers formed on substrate comprises controlling vaporization so that phosphor layer is deposited on substrate in reduced thickness

摘要

Improving the optical separation of needle-like phosphor layers formed on a substrate by vaporizing comprises controlling the vaporization in such a way that the phosphor layer is deposited on the substrate in a thickness which is less than thickness of the phosphor material present as the solid body. Preferred Features: The thickness is reduced by 5-50%. A cooled vapor stream is led onto the substrate to vaporize the phosphor layer. The stream is cooled using a cooled inert gas. The pressure of the inert gas is 1-3 Pa.