Mn-Na共掺ZnO非极性薄膜的结构及其光电磁性能研究

Study on the structure,optical,electrical and magnetic properties of Mn-Na codoping ZnO nonpolar thin films

非极性方向生长的ZnO基多量子阱消除了量子限域Stark效应,可以提高光电器件的发光效率.据此我们采用脉冲激光沉积方法在r面蓝宝石衬底上生长了高质量的α面(11(?)0)单一取向非极性Zn(Mn,Na)O薄膜.X射线衍射、场发射扫描电子显微镜、Hall测试、X射线光电子能谱等测试结果表明:衬底温度和生长气压对Zn(Mn,Na)O薄膜的非极性生长影响很大,在600℃和0.02 Pa条件下实现了Mn-Na共掺,得到了高结晶质量并具有良好光电性能的非极性Zn(Mn,Na)O薄膜.此外,我们还利用超导量子干涉仪研究了Zn(Mn,Na)O薄膜的生长取向对其室温铁磁性能的影响规律,并对引起磁性变化的机理进行了讨论.

Nonpolar Zn（Mn,Na）O thin films with orientation（a-plane） have been successfully grown on r-plane sapphire substrates by pulsed laser deposition（PLD） through a Mn-Na codoping route.The X-ray diffraction（XRD）,field-emission scanning electron microscopy（FE-SEM）,Hall-effect and X-ray photoelectron spectroscopy（XPS） measurements show that growth temperature and work pressure have significant influences on the microstructure and properties of the as-prepared nonpolar Zn（Mn,Na）O.The films prepared under the conditions of the oxygen pressure of 0.02 Pa and the growth temperature of 600℃were of high crystallinity with fine optical and electrical properties.Moreover,the influence of the growth orientation on room temperature ferromagnetism（RTFM） of the thin films has been investigated by superconducting quantum interference device（SQUID）,and the possible mechanism concerning the origin of RTFM observed in the Zn（Mn,Na）O films is discussed as well.