Improving color rendering of Y3Al5O12:Ce3+ white light-emitting diodes based on dual-blue-emitting active layers

An InGaN/GaN blue-violet light-emitting diode (LED) structure and an InGaN/GaN blue LED structure were grown sequentially on the same sapphire substrate by metal-organic chemical vapor deposition (MOCVD). At the low injection current, the intensity ratio of blue-violet light to blue light was almost constant, while the blue light intensity increased gradually with increasing injection current when the latter was more than 40 mA. High color rendering has been realized for a Y3Al5O12:Ce3+ phosphor-converted white LED based on dual-blue-emitting active layers relative to a single blue-emitting active layer at the same injection current. (C) 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim