Effect of Rb+ Doping on Tunable Luminescence in Yb3+/Er3+–Y2O3 Film

Abstract

In this paper, a series of Rb+-doped Er3+/Yb3+–Y2O3 films were synthesized via a sol-gel method and spin coating. The structure and morphology of the samples were investigated by X-ray diffraction and scanning electron microscopy. The Rb+-doped films with nanoparticles, in the size range of 20–40 nm, were obtained. The spectroscopic analysis of the samples was investigated by using the emission spectra and the intensity of luminescence. All the samples exhibited a green emission ascribed to 2H11/2/4S3/2 to 4I15/2 of Er3+ and a red one ascribed to 4F9/2 and its stark level to 4I15/2 of Er3+. As the Rb+ concentration increased, the intensities of the green light and red light were enhanced 16.97- and 5.81-fold relative to that of the undoped sample. Moreover, by controlling the Rb+ concentration, the samples were capable of generating color-tunable luminescence from red to green linearly. The tunable emission was caused by the change of ion distribution ratio in 4F7/2(Er) and 4F9/2(Er) levels. The results suggest that the as-prepared Rb+-doped Er3+/Yb3+–Y2O3 films have a great potential for applications of luminescence.