ZnGa2O4长余辉发光特性的研究  

Effects of Preparation Parameters on the Long Lasting Luminescence of ZnGa_2O_4

作　　者：黄尚永[1,2] 张希清[1] 黄海琴[1] 姚志刚[1] 

机构地区：[1]北京交通大学光电子技术研究所,发光与光信息技术教育部重点实验室,北京100044 [2]北京建筑工程学院物理实验室,北京100044

出　　处：《光谱学与光谱分析》2008年第12期2777-2780,共4页Spectroscopy and Spectral Analysis

基　　金：“973”计划项目(2003CB314707);国家自然科学基金项目(60476005,50532090);北京交通大学重点项目(S07J0020)资助

摘　　要：以ZnO和Ga2O3为原料,采用高温固相法,在不同温度和原料配比下合成了ZnGa2O4。用254 nm的紫外灯照射样品后,发现存在余辉发光,有505和690 nm两个余辉峰,且余辉峰相对强度受原料配比和烧结温度等制备条件的影响。ZnO不足和温度较高时505 nm峰相对强度较高,ZnO过量和温度较低时690nm峰相对强度较高。讨论了余辉峰的来源,认为505 nm峰来源于结构中Ga3+替代了部分Zn2+后相对变形八面体中Ga3+的2EA→4A2能级间跃迁;而690 nm峰起源于晶格中出现氧空位V0*后变形八面体中氧空位向其周围的O2-的V0*→O2-跃迁。解释了余辉峰相对强度受制备条件影响的原因:温度较高时ZnO较多挥发导致不足,而ZnO不足会使结构中出现Zn2+空位,从而多余的的Ga3+出现在这些空位上,其2EA到4A2能级间跃迁使505 nm发射占优;而温度较低时ZnO挥发较少,由于ZnO相对Ga2O3氧不足,可形成更多的O空位,有利于690 nm发射占优,这与余辉峰来源的讨论相符合。Using high temperature solid state reaction method,ZnO and Ga2O3 with high purity as raw materials,different ZnGa2O4 samples were prepared at different molar ratios of raw materials and different temperatures,After excitation of the ZnGa2O4 samples by 254 nm UV lamps, obvious long lasting luminescence was detected for the first time,which showed two new long lasting luminescence peaks at 505 nm and 690 nm,respectively.And the relative intensity of the two peaks was effected by the preparation conditions such as molar ratio of the two raw materials and the sintering temperature.Less ZnO or higher temperature will strengthen the relative intensity of the 505 nm peak,while more ZnO or lower temperature will strengthen the relative intensity of the 690 nm peak.The origin of the two peaks was discussed based on some corresponding documents,and the conclusion is that the 505 nm peak comes from the ^2EA→^4A2 transition of Ga^3＋ in a relatively distorted octahedral after some Zn^2＋ are substituted by Ga^3＋;and the 690 nm peak comes from the V0^＊→O^2-transition after the singly charged ion oxygen vacancies appeare in the octahedral structure.The reasons why the preparing conditions can affect the relative peak intensity of the two peaks were also discussed.Less ZnO will cause Zn^2＋ vacancies in the structure and more Ga^3＋ will occupy the Zn^2＋ positions,then will form distorted octahedral,and then the transition from energy level ^2EA to ^4A2 of Ga^3＋ will cause the 505 nm peak to be dominant.On the other hand,too much ZnO will form oxygen vacancies,which will cause the 690 nm peak to be dominant.Higher temperature will cause more evaporation of ZnO and then relative less ZnO,and lower temperature will cause less evaporation of ZnO and then more oxygen vacancies.These conclusions are corresponding with the origin of the two peaks discussed before.

关 键 词：ZnGa2O4 长余辉 原料配比 烧结温度 发光特性 

分 类 号：O482.3[理学—固体物理]