溅射气压对ZnO薄膜生长、发光性能和结构的影响

沉积缺陷少、晶粒高度c轴择优生长的ZnO薄膜是制备短波发光器件和压电谐振传感器的关键问题之一.以ZnO为靶材,采用射频磁控溅射法在玻璃衬底上制备纳米ZnO薄膜,实现了室温下强的紫外受激发射和弱的深能级发射.通过对薄膜表面形貌的观测, 以及对X射线衍射(XRD)谱和室温光致发光(PL)谱的分析,研究了不同溅射气压对ZnO薄膜生长、结构和发光性能的影响.结果显示溅射气压在1.9 Pa-3.5 Pa之间,晶粒直径先增大后减小,在2.6 Pa时晶粒生长到最大;在3.2 Pa时薄膜单一取向性最优,以此推断最佳的溅射气压在2.6 Pa-3.2 Pa之间.实验在玻璃衬底上制备出了XRD衍射峰半高宽仅为0.12°的、高度c轴择优生长的ZnO薄膜.

The Effect of Air Pressure on the Growth, Crystallization and Photoluminescence of ZnO Films

The ZnO thin films which have unabridged fabric and are highly c-axis oriented is essential to the preparation luminescence apparatus which eradiate shortwave and piezoelectric film resonator. High quality crystal ZnO thin films have been deposited by RF magnetron sputtering on glass substrates. Strong UV photoluminescence and feeble deep energy eradiation are observed at room temperature. Under the different air pressures samples are studied by X-ray diffraction (XRD), PL (photoluminescence) spectrum and AFM. The surface, growth, crystallization condition and photoluminescence are analyzed. When the air pressure is in the range of 1.9 Pa-2.6 Pa, the diameter of grain will increase, when the air pressure augments from 2.6 Pa to 3.5 Pa, the diameter of grain will decrease. When the air pressure is 3.2 Pa, the grains are highly c-axis oriented compared with others. So the optimal air pressure is in the scope of 2.6 Pa-3.2 Pa. Highly c-axis uniquely oriented ZnO thin films with the FWHM of only 0.12° is deposited.