400nm InGaN/GaN and InGaN/AlGaN multiquantum well light-emitting diodes

400 nm In_0.05Ga_0.95N/GaN MQW light emitting diode (LED) structure and In_0.05Ga_0.95N/Al_0.1Ga_0.9N LED structure were both prepared by organometallic vapor phase epitaxy (OMVPE). It was found that the use of Al_0.1Ga_0.9N as the material for barrier layers would not degrade crystal quality of the epitaxial layers. It was also found that the 20 mA electroluminescence (EL) intensity of InGaN/AlGaN multiquantum well (MQW) LED was two times larger than that of the InGaN/GaN MQW LED. The larger maximum output intensity and the fact that maximum output intensity occurred at larger injection current suggest that AlGaN barrier layers can provide a better carrier confinement and effectively reduce leakage current.