In conventional white-light LEDs, a semiconductor emits blue light. The blue light passes through the phosphor and becomes white light. The phosphor is thin film on a substrate; the substrate has to be placed in intricate proximity to [...]]]> According to CNET, Cyberlux are developing white LEDs combining an inorganic semiconductor with an organic phosphorescent layer:

In conventional white-light LEDs, a semiconductor emits blue light. The blue light passes through the phosphor and becomes white light. The phosphor is thin film on a substrate; the substrate has to be placed in intricate proximity to the semiconductor. Positioning the phosphor is one of the more expensive steps in creating an LED, Schmidt said.
In the coming prototype, the conventional phosphor is replaced with a sheet of polymer, which sort of applies itself to the LED, almost like a layer of shrink wrap. The technology was invented by UC Santa Barbara’s Steven DenBaars, who has been a big advocate of LED lighting as a way to increase energy efficiency and reduce greenhouse gases, and Nobel Prize winner Alan Heeger. Heeger also helped found solar-technology company Konarka Technologies.