Luminescent Performances of Green InGaN/GaN MQW LED Employing Superlattices Strain Adjusting Structures

Green InGaN/GaN multiple quantum well(MQW) LEDs employing InGaN/GaN superlattice(SL) structure were studied.The distribution of indium within the MQWs is changed by inserting the InGaN/GaN SL.Meanwhile,the average indium content of MQW does not change.Two InGaN-related peaks that were clearly found in the electroluminescence(EL) and photoluminescence(PL) spectrum,which are assigned to In-rich quantum dots(QD) and the InGaN matrix,respectively.It is suggested that the carrier drifts from the InGaN matrix to the In-rich QD.It could be concluded that employing SL structures is an effective way to adjust the wavelength of InGaN/GaN MQW without introducing new defects in the MQWs.