In a preferred embodiment, the LED has double heterojunction structure having {HEAD ~ a semiconductor active layer} between {TAIL ~ two confinement layers} 
between
In a preferred embodiment , the LED has double heterojunction structure having { HEAD ~ a semiconductor active layer } between { TAIL ~ two confinement layers }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL