ZnO/ZnMgO quantum well lasers for optoelectronic applications in the blue and the UV spectral regions

The electronic and the optical properties of ZnO/ZnMgO quantum well (QW) lasers are investigated numerically by using the non-Markovian gain model with many-body effects. These results are compared with those of GaN/AlGaN QW lasers with spontaneous (SP) and piezoelectric (PZ) polarizations grown on a GaN substrate. The heavy-hole effective mass of the ZnO/ZnMgO QW are shown to be relatively smaller than that of the GaN/AlGaN QW. The heavy-hole effective masses of ZnO/ZnMgO and GaN/AlGaN QWs are 0.89 and 1.48, respectively. The optical gain of the ZnO/ZnMgOQW laser is much larger than that of the GaN/AlGaN QW laser. This is attributed to the fact that the ZnO/ZnMgO QW structure has larger optical matrix elements than the GaN/AlGaN QW structure. These results show that ZnO-based QW lasers are promising candidates for optoelectric applications in the visible and the ultraviolet (UV) regions.