退火对磁控溅射掺铕氧化钇薄膜光致发光谱的影响  

Thermal Annealing Effect on Photoluminescence of Y2O3∶Eu^ 3+Thin Films Prepared by Magnetron Sputtering

作　　者：林舜辉[1] 张李辉 刘勇权 王孝坤 林春雷 余云鹏[1] LIN Shun-hui;ZHANG Li-hui;LIU Yong-quan;WANG Xiao-kun;LIN Chun-lei;YU Yun-peng(Research Center for Advanced Optics and Photoelectronics,College of Science,Shantou University,Shantou 515063,China)

机构地区：[1]先进光学与光电子学研究中心,汕头大学理学院,广东汕头515063

出　　处：《光谱学与光谱分析》2020年第11期3336-3340,共5页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金项目(11674209);广东省自然科学创新团队项目(2018KCXTD011)资助。

摘　　要：稀土掺杂荧光薄膜的发光性能与薄膜所经历的后退火处理密切相关。为了解退火对磁控溅射制备的Y2O3∶Eu^3+薄膜发光性能的影响,在三种不同的工艺条件下,采用射频磁控溅射方法制备了三组厚度100多纳米的Y2O3∶Eu^3+薄膜样品,并在氧气气氛和常压条件下对每组的四个样品分别进行室温、 700、 900和1 100℃的2 h退火处理。样品的X射线衍射谱(XRD)、电子能量色散谱(EDS)、光致发光(PL)及其激发光谱的测量结果表明,虽然薄膜是在不同条件下溅射得到的,但经相同的退火处理后,它们的发光和结构却都呈现出相同的变化规律。首先,薄膜荧光的主激发机制不受退火温度的影响,都是波长为252 nm的电荷转移激发。其次, 700℃退火处理仍不能有效地改变薄膜的弱发光性能;当退火温度达到900℃时,伴随着薄膜中立方相晶粒的增大,发光强度也得以显著提升,薄膜在252 nm光激发下发射出中心位于612 nm的立方相特征主峰;当薄膜经历1 100℃退火处理后,膜内发生了从立方相到单斜相为主的结构相变,此时,膜中Eu对Y的原子数含量比被明显降低至0.05%左右,但光发射效率和强度却得以提高,发射光谱呈现出以5D0→7F2电偶极跃迁的623 nm为主峰的单斜相强发光特征,同时,5D0→7F1磁偶极跃迁的发光也比立方相的明显增强。这些结果可归因于发光中心Eu^3+在单斜结构中占据了更多的非中心对称格位,以及高温退火导致薄膜较好的结晶度。另外还发现,立方相Y2O3∶Eu^3+的5D0→7F0电偶极跃迁581 nm发光峰很弱,而单斜相Y2O3∶Eu^3+在该处的发光却相当明显,此特征可以作为薄膜中单斜相形成的一个提示信号。这个工作展示了磁控溅射制备的Y2O3∶Eu^3+薄膜的退火效应,提供了一种制备具有更好的红光发射性能的纳米单斜相Y2O3∶Eu^3+薄膜的实验方法,并揭示了这种薄膜从纳米立方相到单斜相转变时PL谱的�Fluorescent performance of rare earth doped luminescent film is closely related to post-annealing treatment.In order to explore the influence of thermal annealing on luminescence and structure of Y 2O 3∶Eu ^3+thin films prepared by magnetron sputtering,three groups of the films with thickness of 100~150 nm were deposited on silica glass substrates under three different conditions respectively.Each group contained four samples,which were prepared under the same condition and annealed respectively at room-temperature,700,900 and 1100℃for 2 h in O 2 ambience.The measurements of X-ray diffraction spectra(XRD),electron energy dispersion spectra(EDS)and photoluminescence spectra(PL)were conducted on the films,and the results were summarized as follow:Although the Y 2O 3∶Eu ^3+thin films prepared under different sputtering conditions,the annealing effects on these films are found to be similar if they experience the same annealing process.Firstly,the PL excitation spectra indicate that charge transfer mechanism is responsible for the luminescence of all the films,and the characteristic wavelength(~252 nm)corresponding to this mechanism does not vary with the annealing temperature.Secondly,annealing treatment at 700℃cannot significantly improves the crystallinity and the light emission intensity of the films.When annealing temperature reaches 900℃,the annealed film contains cubic phase Y 2O 3∶Eu ^3+nanocrystallites,leading to the main peak at 612 nm enhanced significantly.However,as the temperature increased to 1100℃,a phase transition from cubic to monoclinic occurs,and the film structure is dominated by the monoclinic phase.Although the content ratio of Eu to Y in the film is decreased to 0.05%after being annealed at 1100℃,the light emission efficiency increases obviously.This result is ascribed to an improved crystallinity and a fact that there are more sites with anti-inversion symmetry in monoclinic lattice than in cubic one.In this case,not only is the red-light emission stronger,but also the main p

关 键 词：掺铕氧化钇 光致发光 退火 单斜相 磁控溅射 

分 类 号：O433.4[机械工程—光学工程]