Formation of magnetic quantum wells based on oxide semiconductors and observation of magneto-optical effects

本论文主要研究基于量子阱结构的磁光材料的发展。我们制备了磁性离子与激子空间分离的ZnCoO/ZnO量子阱。分别使用了氧化锌和氧化锌作为阻挡层.锌铜氧化物作为氧化锌的量子垒，表现出较大的S、p-d交换作用。此外，用X射线光电子能谱测得了氧化锌和氧化锌之间的能级偏移量为160 meV。从X射线衍射谱可以看出，我们得到了高结晶度的锌钴氧化物/氧化锌超晶格。最后，我们在量子阱的能带边缘观察到了与自旋相关的塞曼分裂。然而，由于Co离子中的电荷转移激发，量子阱中的激子发射受到了抑制。

This study focuses on development of magneto-optical materials based on a quantum well structure. We fabricated ZnCoO/ZnO quantum wells with spatial separation between magnetic ions and excitons. ZnO and ZnCoO were used as well and barrier layers, respectively. ZnCoO acts as a quantum barrier for ZnO and shows large s,p-d exchange interaction. Furthermore, band offset between ZnCoO and ZnO was determined as 160 meV, as measured by x-ray photo-emission spectroscopy. From x-ray diffraction, we confirmed high crystallinity of ZnCoO/ZnO superlattices. Finally, we observed a spin-related Zeeman splitting at the band edge of the quantum wells. However, excitonic emissions from the quantum wells were suppressed because of charge-transfer excitation in a Co ion.