稀土离子掺杂的氧化物薄膜制备及性质研究

发布时间：2018-05-14 21:38

本文选题：稀土离子掺杂 + LiNbO_3　；参考：《曲阜师范大学》2017年硕士论文

【摘要】：铌酸锂(LiNbO3)有大的铁电、压电、电光、声光、非线性光学等性质,可广泛被用于光波导调制器、传感器、偏振器等光波导器件的制备。光学器件是集成光学中非常重要的组成部分,薄膜材料制备的器件在很多方面优于体材料器件,因此在硅基片上沉积LiNbO3(LN)薄膜并对其性质进行研究将会对集成光学器件研究及光通信的发展起到一定的促进作用。氧化锌(ZnO)能带隙大、激子束缚能高是很好的掺杂基质,可用于照明、太阳能电池、导电薄膜等研究领域。稀土离子有丰富的能级结构、发光范围宽,多被应用于制备有源器件。Er离子的跃迁4I13/2→4I15/2发射波长约为1.54μm,该波段对应着平面波导的最低损耗传输窗口。常温下铕离子的跃迁5D0→7I2发射波长为618nm,多被用于信号灯、探针、固体激光材料、医疗等领域。现在利用脉冲激光沉积技术制备出传输损耗低、荧光强度大的有源氧化物薄膜研究还不是很多,灵活控制稀土离子在薄膜中的掺杂浓度并研究稀土离子浓度对薄膜结晶质量影响的也不是很多。因此课题组运用脉冲激光沉积技术通过改变实验沉积条件在SiO2/Si(111)衬底上制备了多组择优取向的氧化物薄膜,并利用X射线衍射仪、台阶仪、棱镜耦合设备、荧光光谱仪、高倍镜、冷场发射扫描电镜对制备的样品进行各种物理性质表征,下面是具体的研究内容及研究结果:1.利用PLD技术在SiO2/Si(111)衬底上沉积了择优取向的LN薄膜,探究了O2/Ar气氛、衬底温度、氧压、脉冲激光重复频率、腔外退火处理对薄膜质量的影响,得出利用此设备制备择优取向LN薄膜的最佳实验参数组合:衬底温度500℃,衬底-靶材距离4cm、激光重复频率3Hz、氧压2.0Pa、800℃腔外退火处理、LN陶瓷靶。测试薄膜光波导性质、表面形貌时发现:沉积时间短的样品表面很光滑、晶粒致密但是厚度(200nm)太薄光很容易进入到衬底中去,很难形成波导;沉积时间长的样品厚度足够形成波导但是薄膜表面出现很多裂纹,目前课题组还没把光耦合进样品中去。2.利用PLD技术通过改变实验条件在SiO2/Si(111)衬底上制备了多组择优取向的Er:LN薄膜,实验中选择的沉积靶材不是固定比例的Er:LN复合靶,是Er2O3与LN双靶交替与脉冲激光作用沉积Er:LN薄膜,从而可以灵活控制稀土离子的掺杂浓度。探究了衬底温度、氧压、铒靶生长时间对Er:LN薄膜质量的影响,发现衬底温度越高、氧压越大薄膜结晶质量相对越好,当沉积薄膜厚度为800nm时薄膜结晶质量降低为多晶。测试样品的光致荧光性质时选用波长为532nm激光泵浦样品,实验开始前在样品腔进光口处放置840nm滤光片有效排除倍频光的影响,测试结果显示样品在1537nm处有很强的光致发光峰,Er:LN薄膜结晶质量很好。3.利用PLD技术在SiO2/Si(111)衬底上制备了择优取向的Eu:ZnO薄膜,探究了衬底温度、氧压、脉冲激光重复频率、生长时间对薄膜质量的影响。衬底温度300℃、氧压1.0Pa、脉冲激光重复频率5Hz薄膜结晶质量较好,沉积时间越长样品的(002)衍射峰越强,薄膜厚度对Eu:ZnO薄膜的结晶质量影响不是很明显。用氙灯泵浦样品,泵浦波长为466nm、样品前放置510nm波长的滤光片,在618nm处检测到样品的光致发光峰强度比靶材的还要高,说明沉积的Eu:ZnO薄膜结晶质量比较高。
[Abstract]:Lithium niobate (LiNbO3) has large ferroelectric, piezoelectric, electro-optic, acousto-optic, nonlinear optical properties, and can be widely used in the fabrication of optical waveguide devices such as optical waveguide modulator, sensor, polarizer and so on. Optical devices are an important part of integrated optics. The devices made by thin film materials are better than bulk materials in many aspects. Therefore, silicon is used in silicon The deposition of LiNbO3 (LN) film on the substrate and its properties will play a certain role in the development of integrated optical devices and optical communication. Zinc Oxide (ZnO) has large band gap, high exciton binding energy is a good doping matrix, can be used in the field of lighting, solar cells, conductive films and so on. Rare earth ions have rich energy. It has a wide range of luminescence and is widely used in the transition 4I13/2 to 4I15/2 emission wavelength of the active device.Er ion. The emission wavelength is about 1.54 mu m. This band corresponds to the lowest loss transmission window of the planar waveguide. The emission wavelengths of the europium ions in 5D0 to 7I2 at normal temperature are 618nm, and are mostly used in the fields of signal lamps, probes, solid laser materials, medical treatment and so on. Now, the pulse laser deposition technology has been used to prepare the active oxide thin films with low transmission loss and high fluorescence intensity. It is not much to control the doping concentration of rare earth ions in the thin films and to study the influence of the concentration of rare earth ions on the quality of the thin films. A variety of preferred orientation oxide films were prepared on SiO2/Si (111) substrate by changing the experimental deposition conditions. The samples were characterized by X ray diffractometer, step meter, prism coupling equipment, fluorescence spectrometer, high magnification mirror and cold field emission scanning electron microscope. The following is the specific research content and research results: 1. profit. The preferred orientation LN films were deposited on SiO2/Si (111) substrate by PLD technology. The effects of O2/Ar atmosphere, substrate temperature, oxygen pressure, pulse laser repetition rate and annealing treatment on the film quality were investigated. The optimum test parameters for the preparation of preferred orientation LN films were obtained by using this device: substrate temperature 500, substrate range 4cm, excitation. The optical repetition frequency 3Hz, oxygen pressure 2.0Pa, 800 C external annealing treatment, LN ceramic target. Testing the properties of thin film optical waveguide, the surface morphology shows that the surface of the sample with short deposition time is very smooth, the grain is compact but the thickness (200nm) thin light is easy to enter the substrate, it is difficult to form the waveguide; the thickness of the sample with long deposition time is enough to form the waveguide, but it is enough to form the waveguide, but the thickness of the deposition time is enough to form the waveguide, but the thickness of the sample is enough to form the waveguide, but the thickness of the deposition time is enough to form the waveguide, but the thickness of the deposition time is enough to form the waveguide, but the thickness of the deposition time is enough to form the waveguide, but the thickness of the sample is enough to form the waveguide but it is enough to form the waveguide, but the thickness of the sample with long deposition time is enough to form the waveguide but There are a lot of cracks on the surface of the film. At present, the subject group has not coupled the optical coupling into the sample and.2. using PLD technology to prepare a number of preferred orientation Er:LN films on the SiO2/Si (111) substrate by changing the experimental conditions. The selected sedimentary target is not a fixed proportion of Er:LN composite target, which is the alternate and pulse laser of the Er2O3 and LN double targets. With the deposition of Er:LN film, the doping concentration of rare earth ions can be controlled flexibly. The influence of substrate temperature, oxygen pressure and erbium target growth time on the quality of Er:LN film is explored. It is found that the higher the temperature of the substrate, the higher the oxygen pressure is, the better the crystalline quality of the film is. When the thickness of the film is 800nm, the crystalline quality of the thin film is reduced to polycrystalline. 532nm laser pumped samples were selected for the photofluorescence properties. Before the experiment, 840nm filters were placed in the cavity of the sample cavity to effectively eliminate the influence of frequency doubling light. The test results showed that the sample had a strong photoluminescence peak at 1537nm, and the crystal quality of the Er:LN film was very good.3. and PLD technology was used to prepare the SiO2/Si (111) substrate. The influence of substrate temperature, oxygen pressure, pulse laser repetition frequency and growth time on film quality is investigated. The crystallization quality of 5Hz film is 300, 1.0Pa and pulse laser repetition frequency 5Hz film is better. The longer the deposition time is, the higher the (002) diffraction peak, the film thickness has no effect on the crystal quality of Eu:ZnO film. It is obvious that the sample with xenon lamp pump, the pump wavelength is 466nm, the 510nm wavelength filter is placed before the sample, and the photoluminescence peak intensity of the sample is higher than that of the target at 618nm, indicating that the crystalline quality of the deposited Eu:ZnO film is higher.

【学位授予单位】：曲阜师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O484

【参考文献】