Study of composition control and capping of MOVPE grown InGaN/InxAlyGa1-x-yN MQW structures

We report on the growth and characterization of InGaN/InxAlyGa1-x-yN multiple quantum well (MQW) structures emitting at 380 nm. The samples were grown by metalorganic vapour phase epitaxy (MOVPE) and were analyzed by using high resolution X-ray diffraction (HRXRD), room and low temperature photoluminescence (PL) measurements. The effect of changing the indium precursor flow during the barrier and capping layer growth on the structural and optical quality of multiple quantum wells (MQWs) is explored. The HRXRd results show that the MQWs grown under the set of mentioned conditions are of very good structural quality. The temperature dependent PL results from our samples show that increasing the In content in the barriers enhances to a certain limit the internal quantum efficiency of the MQW structures. We also report that changing the In content in the capping layer effect the peak emission energy and does not have any significant impact on the optical quality of the MQW structures. (c) 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.