Optimization scheme for the quantum efficiency of GaInN-based green-light-emitting diodes

We have optimized the internal quantum efficiency (IQE) of GaInN∕GaN quantum-well (QW) structures. For an emission wavelength of 460nm, a high IQE of 73% was achieved. For a longer emission wavelength, calculations predict higher oscillator strength for thinner QWs but higher In content. We observe an improvement in IQE of almost 50% when reducing the QW width from 2.7nmto1.8nm, and increasing the In content for the whole blue to green spectral region with IQE=40% at 525nm. The typical saturation of the output power with increasing current that occurs, particularly for green-light-emitting diodes, is extremely weak in our structures.