Green gap spectral range light-emitting diodes with self-assembled InGaN quantum dots formed by enhanced phase separation

Light-emitting diodes (LEDs) emitting in the green gap spectral range (540-610 nm) were demonstrated using self-assembled In-rich InGaN quantum dots (QDs) grown on n-GaN by metal-organic chemical-vapor deposition. The study of structural and optical properties showed that the formation of InGaN QDs with larger size and higher In composition is enhanced by phase separation in the InGaN layer with increasing surface roughness of the underlying n-GaN layer. The emission wavelength of the LED was redshifted from the green (540 nm) to red (610 nm) spectral range due to an increase in the depth of potential wells of the InGaN QDs with increasing surface roughness of the underlying n-GaN layer.