Engineering the color rendering index of phosphor-free InGaN/(Al)GaN nanowire white light emitting diodes grown by molecular beam epitaxy

The functional properties, such as color rendering index (CRI) and correlated color temperature (CCT) of nanowire white light emitting diodes (LEDs), have been studied. The nanowire LEDs can generate broad spectrum white light, and by controlling the growth conditions, it is easy to tailor the spectrum. This is a significant advantage over phosphor converted or nanocrystal based white light sources since it is difficult to modulate the spectrum while maintaining high efficiency using these conventional methods. The authors demonstrated that the InGaN/(Al)GaN dot-in-a-wire heterostructure LEDs can generate high CRI values of 94-98 in both warm and cool white regions. Furthermore, the generated light demonstrates relatively stable CCT, CRI, and Commission Internationale d'Eclairage coordinates at different injection currents. (C) 2014 American Vacuum Society.