Effect of Zn2+ and Li+ ions doped on microstructure and upconversion luminescence of Y2O3: Er3+-Yb3+ thin films

• Published in: Journal of alloys and compounds Vol. 816; p. 152575
• Main Authors: Sun, Min, Liu, Juncheng, Nie, Lifang
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 05.03.2020; Elsevier BV
• Subjects: Charge compensation; Conversion coating; Doped films; Doping; Erbium; Fluorescence; Ion concentration; Li+-Zn2+ co-doping; Light emission; Lithium ions; Luminescence; Luminous intensity; Sol-gel processes; Spin coating; Thin film; Thin films; Up-conversion luminescence; Upconversion; Y2O3; Ytterbium; Yttrium oxide; Charge compensation; Up-conversion luminescence; Y2O3; Li+-Zn2+ co-doping; Thin film
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2019.152575

The Y2O3 up-conversion luminescent films were prepared with sol-gel and spin coating. The effects of Li+ doping, Zn2+ doping and Li+-Zn2+ co-doping on the structure and upconversion luminescence property of the samples were investigated. The results show that the doping improved the film’s crystallinity, and the effect of co-doping was better than that of single doping. Pumped with 980-nm laser, there were three emission bands in the up-conversion spectrum of each sample, 553-nm and 563-nm green lights, and 683-nm red light, corresponding to Er3+: 2H11/24I15/2, 4S3/2→4I15/2, 4F9/2→4I15/2 transitions, respectively. Although the ion concentration of the single-doped Li+ (3.0 mol%) or the single-doped Zn2+ (3.0 mol%) was the same as that of the Li+-Zn2+ co-doped (1.5 mol%+1.5 mol%), the 563-nm green light emission intensities of the three doped films were about 3.2, 6.4 and 18 times of that of the undoped, respectively. The doped Li+ or Zn2+ ions further broken the symmetry of the Y2O3 crystal field, restrained the fluorescence quenching, and increased the fluorescence lifetime, therefore improved greatly the luminescence intensity. When Li+ and Zn2+ ions were co-doped, their charge compensation effect further improved the fluorescence lifetime and the luminescence intensity. •Li+ doping increased 563-nm emission intensity of Yb3+/Er3+ doped Y2O3 film 2.2 times.•Zn2+ doping increased 563-nm emission intensity of Yb3+/Er3+ doped Y2O3 film 5.4 times.•Li+-Zn2 co-doping increased 563-nm emission intensity of Y2O3 film 18 times.•The enhancement effect of co-doping far above the single doping one is mainly due to the charge compensation.•The co-doping also increased the fluorescence lifetime of Y2O3 film by more than 2 times.