(Cu,Al)掺杂ZnO薄膜表面处缺陷的拉曼光谱研究

采用电感耦合等离子体增强物理气相沉积法制备了(Cu,Al)掺杂ZnO薄膜,超导量子干涉磁强计测试结果表明,薄膜具有室温的铁磁性。采用激光共聚焦拉曼(Raman)光谱研究了(Cu,Al)掺杂ZnO薄膜的表面特性,以两种处理方式对薄膜进行了Raman光谱测试:共聚焦模式从薄膜表面开始至不同深度处进行测试;对薄膜样品进行预处理加工,采用面扫描模式在薄膜平面对(Cu,Al)掺杂ZnO薄膜的斜面进行测试。分析了Raman光谱A₁(LO)峰的中心位置和强度变化,结果表明,界面处晶格应力和缺陷明显增强。这些晶格畸变和点缺陷的存在会对体系的铁磁性有促进作用。

Defect Study at The Surface of (Cu,Al)-doped ZnO Thin Film by Raman Spectra

(Cu,Al)-doped ZnO thin films were deposited by an inductively coupled plasma enhanced physical vapor deposition system. The magnetic properties were measured by a superconducting quantum interference device magnetometer, and room-temperature ferromagnetism was observed in the (Cu,Al)-doped ZnO thin films. The surface characteristics of (Cu,Al)-doped ZnO thin films were studied by confocal Raman spectroscopy. Two different Raman spectra were performed: A confocal Raman measurement was used to characterize the defects at the surface and interface by focusing at different depths; A mapping mode was performed along a slope which was processed by a mask. The central position and the intensity of A1(LO) resonance peak were analyzed. The results indicate that the lattice stress and defects at the interface were obvious, while these lattice stress and defects at the interface will enhance the ferromagnetic properties of (Cu,Al)-doped ZnO thin films.