{HEAD ~ The electron hole pairs} trapped within the active layer sensitize {TAIL ~ the activator ions}, causing the activator ions to emit light 
sensitize
{ HEAD ~ The electron hole pairs } trapped within the active layer sensitize { TAIL ~ the activator ions } , causing the activator ions to emit light
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH