SnSe晶体是一种新型低成本环境友好型热电半导体材料，近几年已成为国内外研究的热点。为了获得SnSe晶体，目前国际上主要采用垂直布里奇曼法和垂直梯度凝固法两种技术进行生长。然而该材料因具有独特的层状结构和复杂热膨胀特征，其在晶体生长过程中极易发生解理开裂，导致难以获得大尺寸晶体。为了解决高完整SnSe晶体制备难题，本团队在材料体系相图及热重分析指导下，近年来先后开发出了气相法、水平熔体法以及水平液封法等多种晶体制备技术，均成功获得了较大尺寸的SnSe晶体材料。本论文从工艺原理、技术要点、晶体生长结果等多方面对相关技术创新情况予以介绍，并将它们的优缺点进行了对比。综合评价认为水平液封法在获取高完整SnSe晶体及性能调控方面具有显著优势，未来将逐渐成为一种广受欢迎的技术。

A high-quality Cr3+:CdWO4 single crystal at a size of approximately \Phi 25 \times 80 mm is grown using the Bridgman method with CdO, WO3, and Cr2O3 as raw materials and their molar ratio of 100:100:0.5. The temperature gradient of solid-liquid interface at growth is approximately 50 oC/cm and the growth rate is 0.05 mm/h. The X-ray diffraction (XRD), absorption, excitation, and emission spectra of different parts of the as-grown and O2-annealed crystals are investigated. Two strong broad optical absorption bands of about 472 and 708 nm are observed, and they are associated with the transitions 4A2->4T1 and 4A2->4T2. The weak 4T2->2E transition (the R-line) at 632 nm is also observed. The crystal-field parameter Dq and the Racah parameters B and C are estimated to be 1 412.4, 776.8, and 3 427.6 cm-1, respectively, according to the absorption spectra and crystal-splitting theory. A broadband fluorescence at about 1 000 nm due to 4T2->4A2 transition is produced by exciting the samples at 675 nm. After being annealed in an O2 atmosphere, the crystals become more transparent, while the effective light absorption of Cr3+ ions is evidently enhanced and the emission intensity is also strengthened due to the reduction of oxygen vacancies in the CdWO4 crystal after annealing.