Growth and characterization of phosphor-free white light-emitting diodes based on InGaN blue quantum wells and green–yellow quantum dots

•We reported phosphor-free white light-emitting diodes based on InGaN blue quantum wells and green–yellow quantum dots.•The InGaN quantum wells and quantum dots were observed by TEM.•The electroluminescence was studied under different injection currents and different temperature.•The current dependency of electroluminescence spectrum was explained.

Phosphor-free white light-emitting diodes consisting of 4 layers of InGaN/GaN quantum dots and 4 layers of quantum wells have been grown by metal organic chemical vapor deposition. A white emission was demonstrated under electrical injection by mixing the green–yellow light from quantum dots and the blue light from quantum wells. At the injection current of 5 mA, the electroluminescence peak wavelengths of quantum dots and quantum wells were 548 nm and 450 nm, respectively, resulting in the color-rendering index Ra of 62. As the injection current increased, a faster emission enhancement of quantum well and an emission blue shift of the quantum dots were observed, which led to the decrease of Ra.