How long do these organic materials continue to glow after the ongoing excitation? While some materials do glow for hours (dimly), many materials only continue to glow for a fraction of a second. This isn't all bad; people expect a light to go dark after they turn it off. However, a continuing glow for a few seconds might be an interesting feature, it would allow time to leave the room before it went completely dark. (Like the car headlights with a timer that turn them off after a delay.)
Why would one have to wait to have the organic phosphors OLED pannels ? Today you can get high lumens based lighting panels using the same LED light guides technology used in LCD backlighting panels ! This can go up to several hundreds of lumens using only a limited numbers of LEDs.
Solid-state lighting (SSL) today is harnessing arrays of LEDs, some of which fit in the standard light bulb socket. However, some believe that in the future, consumers will abandon the "light bulb" form factor in favor of SSL lighting panels in whatever shape is convenient. Light panels using these organic phosphors could accelerate the day when OLED panels are as bright, but cheaper and more power efficient than LEDs.