在c-plane面蓝宝石衬底上生长了ZnO/Zn0.85Mg0.15O非对称双量子阱, 其内量子效率相对于对称量子阱有了显著的提高。ZnO/Zn0.85Mg0.15O 的10周期对称量子阱和5周期非对称双量子阱都是利用等离子体辅助分子束外延技术制备的。ZnO/Zn0.85Mg0.15O非对称双量子阱的内量子效率提高至对称阱的1.56倍。时间分辨光谱和光致发光谱测试结果证实, 在ZnO/Zn0.85Mg0.15O非对称双量子阱中存在从窄阱到宽阱的激子隧穿过程, 这是内量子效率提高的主要原因。

We report a dramatic increase in the internal quantum efficiency (IQE) of ZnO/ZnMgO multi-quantum wells (MQWs) fabricated on c-plane sapphire substrate by introducing asymmetric double-quantum-well (ADQW) structure. A marked enhancement in efficiency, by as much as 1.56 times, was observed for the ZnO/ZnMgO five-period ADQW grown by plasma-assisted molecular beam epitaxy (P-MBE), compared to the ten-period symmetrical MQWs with asymmetric structure. The effects of excitons tunneling from the narrow well to the wide well, which was proved by photoluminescence spectra and time-resolved photoluminescence spectroscopy, can influence the IQE.