日盲紫外光电阴极用碲合金蒸发材料研究  

Tellurium-Based Alloy Used as Evaporator Source for Solar-Blind Photocathode

作　　者：王保光[1] 田文怀[1] Wang Baoguang;Tian Wenhuai(School of Material Science and Engineering, University of Science ＆ Technology Beijing, Beijing 100083, China)

机构地区：[1]北京科技大学材料科学与工程学院

出　　处：《稀有金属》2018年第5期503-509,共7页Chinese Journal of Rare Metals

基　　金：国家自然科学基金项目(50761012)资助

摘　　要：选择铋作为合金化元素,利用真空熔炼慢速凝固方法制备出Te60Bi40（%,质量分数）合金来代替纯碲作为日盲光电阴极的碲蒸发源。利用光学显微镜（OM）、X射线衍射仪（XRD）、扫描电子显微镜（SEM）以及能谱仪（EDS）等方法对制备的Te60Bi40合金样品进行了微观组织观察,对合金的相组成、相结构以及各相的成分进行了分析。结果表明：利用真空熔炼慢速凝固方法制备的Te60Bi40合金由初晶Bi2Te3和共晶（Bi2Te3＋Te）相组成,得到了近平衡相。初晶Bi2Te3晶粒为粗大的板条状,板条平均宽度为300μm,晶界较平直有棱角,呈现小平面相特征。共晶Bi2Te3相以片条状的形态均匀分布在共晶Te相中。在共晶凝固过程中,由于共晶Bi2Te3相和Te相的热导率和熔化潜热有较大的差异,Te相在凝固时作为领先相生长,滞后相Bi2Te3最终被领先相Te相完全包裹。初晶Bi2Te3相和共晶Bi2Te3相中Te的质量分数分别为49.2%和49.6%,共晶Te相中Te的质量分数接近100%。Bismuth was selected as the alloying element to prepare Te60 Bi40(%,mass fraction） alloy. The alloy prepared by vacuum melting with a slow solidification speed was used as tellurium atom evaporation source instead of pure tellurium for ultraviolet detection photocathode. Optical microscope(OM）,X-ray diffraction(XRD）,scanning electron microscope(SEM）,energy dispersive spectrometer(EDS） were used to investigate the microstructure,phase constitution,phase structure and composition of each phase in the as-prepared alloy. The results showed that the Te60 Bi40 alloy prepared by vacuum melting with a slow solidification speed obtained nearly equilibrium phases which were composed of primary Bi2 Te3 phase and eutectic(Bi2 Te3＋ Te） phases. The primary Bi2 Te3 phase was thick lath-shipped with an average width of 300 μm and presented the characteristic of faceted phase with relatively flat and angular boundaries. The eutectic Bi2 Te3 phase in form of strip evenly distributed in the eutectic Te phase. Owing to the relatively large difference between thermal conductivity and latent heat of fusion of Bi2 Te3 and Te phases,Te phase gained a lead during solidification and the lagging Bi2 Te3 phase was encased by the leading Te phase at last. The mass content of Te in primary Bi2 Te3 phase and eutectic Bi2 Te3 phase was 49. 2% and 49. 6%,respectively,and the mass content of Te in eutectic Te phase was close to 100%.

关 键 词：碲铋合金 共晶 小平面相 日盲紫外 

分 类 号：TG113.12[金属学及工艺—物理冶金]