Investigation of optical properties of InGaN–InN–InGaN/GaN quantum-well in the green spectral regime

The optical properties of the InGaN/GaN quantum well with insertion of ultrathin InN layer is investigated by using the effective mass theory taking into account the valence band mixing effects. The total spontaneous emission radiation recombination rate can be optimized by modulating the position of InN layer in the InGaN QW. Meanwhile, it is observed that the difference of the spontaneous emission rate becomes smaller with increasing the sheet carrier density. Then, the influences of intermixing effect at the interface between InN and InGaN layers on the optical gain are analyzed. It shows the emission intensity is reduced as compared to the ideal QW structure while peak wavelength is red-shifted by ∼10 nm in the investigation range of Lsn. Finally, the influence of partial strain relaxation on the lasing wavelength is discussed, which shows a blue shift of ∼27 nm in the case with residual strain of 50% in comparison to the no strain relaxation case.