A lamp including a first and second lamp substrate with a first and second external electrode, respectively, and a first and second internal phosphor coating, respectively, wherein the first phosphor coating is a phosphor monolayer. A method of manufacturing a lamp, including screen-printing a phosphor monolayer on a first lamp substrate; screen-printing a phosphor layer on a second lamp substrate; joining the phosphor-coated faces of the first and second lamp substrates together with a seal; and joining a first and second electrode to the uncoupled exterior faces of the first and second lamp substrates, respectively.