氧浓度对MS法制备的ZnO:Sb薄膜的光学性能影响

Influence of O_2 Concentration on Optical Properties of ZnO:Sb Thin Films Prepared by Magnetron Sputtering

在玻璃衬底上以Zn-Sb合金靶为靶材,采用射频反应磁控溅射法制备出具有良好C轴取向的ZnO:Sb薄膜。用X射线衍射仪、分光光度计和荧光发光光度计等测试手段分析了Sb掺杂ZnO薄膜的晶体结构和光学性质。薄膜在N2气中550℃退火后的X射线衍射谱表明:Sb掺杂ZnO薄膜主要沿ZnO的(002)方向生长,没有检测到其它杂质相的生成。退火前,薄膜的光学带隙随氧浓度的增大而增大,退火后薄膜光学带隙减少。薄膜的室温光致发光谱中有较强的蓝光发射峰,并对蓝光的发射机理作了分析:蓝光(487 nm左右)的发射与锌填隙(Zn i)和锌空位(VZn)缺陷能级有关,还与Sb3+离子提供了相应的蓝光中心有关;蓝光峰(436 nm左右)的发射与锌填隙缺陷能级和氧空位(VO)形成的浅施主能级有关,这些蓝光峰的出现对于开发出单色蓝光发光器件有重要意义。

With Sb-doped ZnO films deposited on glass substrates by RF reactive magnetron sputtering, the optical band gap of films increases with the increasing of oxygen concentration before anneal and decreases after anneal in nitrogenthe. The films show good transmissivity in the visible-near infrared. X-ray diffraction results indicate that the Sb-doped ZnO films grow along the ZnO （002） direction and have highly C-axis preferred orientation after anneal in nitrogenthe 550 %. No manganese oxide or nitride phase are detected after annealing in nitrogenthe 550 ℃ later. The strong blue emission peaks are observed at room temperature photoluminescence spectra of films and the luminescence mechanism of the blue is also discussed. The blue light emission（ about 487 nm） is related to Zni （zinc interstice） ,VZn （zinc vacancy） defect levels and the corresponding blue light center which the Sb^3＋ ions provides with;The blue light peak （ about 436 nm） is related to Zni （ zinc interstice） defect levels and the shallow donor level which VO （ oxygen vacancy） forms in the Sb-doped ZnO films. The emergence of Blu-ray peaks have great significance for the development of a monochromatic blue light-emitting devices.