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A new phosphor material could make it possible to replace the mercury in
fluorescent lights with xenon, an inert, eco-friendly gas. Inside strip lights,
electricity passes through mercury vapour, producing ultraviolet radiation. When
this UV strikes the phosphors that coat the inside of the tubes, they emit
visible light, or fluoresce. Existing phosphors, however, cannot convert the
higher energy UV (VUV) produced by xenon. But the new phosphor, developed by
researchers at Utrecht University, emits two visible photons for every VUV
photon it absorbs, giving bright orange and red light (Science, vol
283, p 663). To make white light, blue and green phosphors now need to be
developed.