【作者】 贾丽娟；

【导师】 王倩；

【作者基本信息】 新疆大学 ， 原子与分子物理， 2008， 硕士

【摘要】 Li₂B₄O₇材料在被辐射照射后会储存接受的辐射信息,以光释光或热释光的形式释放出来,其数目与接受的辐射剂量密切相关。这一特性可应用于辐射剂量的测量。并且,该物质的有效原子序数Ze=7.26,十分接近人体组织的有效原子序数（Ze=7.13）,因此在检测射线强度和分辨射线种类方面都有很好的使用前景。在研究热释光与光释光性质之前,对材料的光学性质的研究是十分有必要的,通过光学性质的研究我们可以获得薄膜材料的能级结构、禁带宽度等信息。我们研究了掺杂后的薄膜的光致发光特性,初步研究了杂质的特征发光谱、杂质能级以及发光淬灭中心对薄膜发光特性的影响。为以后的研究工作积累必要的资料。本工作利用溶胶凝胶法、丝网印刷法制备Li₂B₄O₇薄膜,通过X射线衍射测试对薄膜进行定性分析,用可见-紫外分光光度计以及光致发光法测量薄膜的光学性质;并利用金属元素（Cu、In）掺杂对Li₂B₄O₇薄膜进行了光学性质的改性。XRD分析结果表明溶胶凝胶法制备的薄膜杂相较多,这不利于薄膜在辐射剂量学中的应用,因此还需要对溶胶凝胶法进行进一步的改善;丝网印刷法制备的Li₂B₄O₇薄膜,没有杂相,并能够很好的控制膜厚,由于Li₂B₄O₇熔点较高,在高温下不易分解和被氧化,因此在干燥或烧结之后也没有其它相的产生。用Cu、In元素掺杂的方法观察Li₂B₄O₇薄膜的光学性质的变化,实验结果表明,掺杂之后的Li₂B₄O₇:Cu,In薄膜与Li₂B₄O₇:Cu薄膜均存在2种吸收机制、光学禁带宽度均比未掺杂时的窄,这将有利于改善Li₂B₄O₇材料的热释光及光释光性质。光致发光实验结果表明,轻度Cu掺杂能够增大Li₂B₄O₇薄膜的发光强度,但当Cu重度掺杂的时候出现了发光淬灭;Cu、In共掺杂时,发现原先Li₂B₄O₇:Cu薄膜的发光强度随Cu浓度的增加而逐渐减弱。更多还原

【Abstract】 Li₂B₄O₇ materials could store radiation information after being radiated. The energy is released by thermo-luminescence （TL） and optical stimulated luminescence （OSL） manners. The quantity of the energy is according to the tensity of the TL or the OSL. Moreover, the effective atomic number of the Li₂B₄O₇ material （Ze=7.26） is close to the body organizational tissue （Ze=7.13）.Therefore, the material has application prospects in the intensity and the species of ray detection. Before the study of the TL and the OSL properties, it is necessary to study the luminescence properties of the Li₂B₄O₇ material. The methods of films’preparation in this work are the sol-gel method and the silk screen painting method. And the structural information of the films was obtained by the X-ray diffraction （XRD） analysis; we also studied the optical properties through optical absorption and photo- luminescence analysis. Furthermore we improved the film’s optical properties by Cu and In elements doping .The experimental results showed that there were lots of impurity phase in films prepared by sol-gel method, therefore we have to improve the experimental technique in our later works. Because the melt point of the Li₂B₄O₇ material is very high , and it is not easy to decompose and oxidize under the high temperature. The films prepared by the silk screen painting method almost have no impurity phase even after the annealing under the high temperature and the thickness of the films could be controlled better.The Cu and In elements doping experimental results showed that the optical properties changed with the different doping concentration. The results also showed there were two absorption manners for Li₂B₄O₇:Cu ,In and Li₂B₄O₇:Cu films; the forbidden band gap of Li₂B₄O₇ thin films got smaller when they were doped with Cu and In element .These results would be favorable to the TL and OSL properties. The photo- luminescence results showed that slight doping could increase the luminescence intensity, but when the doping concentration is high there was center of luminescence quenching. When doped the Li₂B₄O₇: Cu films with In element at the same time, the luminescence intensity of the Li₂B₄O₇: Cu films reduced as the Cu concentration increased.更多还原