The Preparation And PL Properties Of Er-doped SiO_x And ZnO Films

Due to 1.54 |j.m photoluminescence (PL) of Er3+ from 4I₁3/2-->⁴I15/2 transition, corresponding to the wavelength of maximum transparency of standard silica-based optical fibers, Er-doped materials have played an important role in the development of optical communication technology. With the development of optical communication and integrated optoelectronics, more and more attention is paid to Er3+-doped optical waveguide amplifier (EDWA). Er-doped thin films become the hotspot because of its potential application in the field of optical fiber communication.This thesis is supported by the National Nature Science Foundation of China Grant No. 50240420656. In this study, Er-doped silicon rich SiO2 and ZnO films have been fabricated by Ion-Beam-Assisted-Deposition (IBAD) and Reactive-Magnetron-Sputtering (R.MS) technology respectively. The morphological, microstructures and PL properties of the films are investigated in this work.The major points of this thesis are summarized as follows:1. The ratio of Si to O of Er3+-doped SiOx films synthesized by IBAD decreases from about 3 in the as-deposited film to about 1 in the annealed films. The film as-deposited at 500 °C is amorphous. After annealed at 800 and 1100 ℃ for 2 h, the film structure changes into nc-Si, and the average grain size increases from 10 to 40 nm estimated. The PL spectra of Er-doped materials are sensitive to the thermal annealing process. No PL spectrum is detected from the Er-doped SiOx film as-deposited. The PL intensity increases by about one order with the increase of the annealing temperature up to 800 and 1100 ℃. No obvious saturation of PL intensity can be observed in Er-doped SiOx films when the laser power increases up to 1W.2. The as-deposited Er/Yb co-doped ZnO film synthesized by Radio Frequency Magnetron Sputtering (R.F. Sputtering) at 500 ℃ is the highly c-axis oriented polycrystalline structure. The results of x-ray diffraction analysis show the evolution of the film structure with the annealing temperature can be divided into three stages. Below 900℃, the grain size of the film increases with the increase of annealing temperature. At 900℃, Er2O3 and Yb2O3 phases start to segregate from the ZnO film. When the annealing temperature reaches to 1100℃, the phase of Zn2SiO4 appears due to the reaction of ZnO film with Si chip can be observed. The PL spectra of the films annealed above 900℃ are detected at room temperature and the maximum PL intensity was observed in the film annealed at 1050℃. The relationship between PL properties and the microstructure of the film is discussed in the paper. The influences of annealing temperature on the UV and visible PL properties are studied.3. The microstructure of the as-deposited Er/Yb co-doped ZnO film Synthesized by Pulse MagnetronSputtering (PMS) is same with that obtained by R.F. Sputtering except the grain size is larger than that obtained by R.F. sputtering. The behavior of Er2O3 and Yb2O3 precipitation and phase transition is similar to that of obtained by R.F. sputtering except the Zn2SiO4 phases appear until 1200℃. The stress in the films Synthesized by PMS is less than that by R.F. sputtering. The dependence of PL spectra and intensity on the annealing temperatures in the range of 800℃ -1200℃ is similar to that of the film deposited by RF. The maximum PL intensity obtained at 1050℃, however, is as strong as about 200 times of that measured from the film by R.F. sputtering.