High Efficient Polarization-Matched InGaN/MgZnO Quantum Well Structures

The optical properties of InGaN/MgZnO quantum wells (QWs) with zero internal field were investigated by using the non-Markovian model with many-body effects. For a given In composition in a well, a Mg composition in a barrier was selected to give a zero internal field in a well. The Mg composition in the barrier to give zero internal field is shown to increase with In composition in the well. The InGaN/MgZnO QW structure has shorter transition wavelength than the InGaN/GaN QW structure because the internal field is negligible for the former case. Also, in the case of a relatively high In composition (x >; 0.15), the InGaN/MgZnO system has a much larger spontaneous emission coefficient than the InGaN/GaN system. This can be explained by the fact that an optical matrix element is largely enhanced due to disappearance of the internal field.