无机材料学报 ›› 2024, Vol. 39 ›› Issue (4): 409-415.DOI: 10.15541/jim20230479 CSTR: 32189.14.10.15541/jim20230479

• 研究论文 • 上一篇    下一篇

水热-烧结法制备Cr2+:ZnSe/ZnSe核壳结构纳米孪晶

张婷婷(), 王方园, 刘长友(), 张国荣, 吕佳辉, 宋宇晨, 介万奇   

  1. 西北工业大学 材料学院, 凝固技术国家重点实验室, 西安 710072
  • 收稿日期:2023-10-17 修回日期:2023-11-21 出版日期:2024-04-20 网络出版日期:2023-12-04
  • 通讯作者: 刘长友, 副教授. E-mail: lcy@nwpu.edu.cn
  • 作者简介:张婷婷(2000-), 女, 硕士研究生. E-mail: zhangtt@mail.nwpu.edu.cn
  • 基金资助:
    陕西省重点研发计划(2021GY-202);国家自然科学基金(52072300);国家自然科学基金(61874089)

Hydrothermal-sintering Preparation of Cr2+:ZnSe/ZnSe Nanotwins with Core-shell Structure

ZHANG Tingting(), WANG Fangyuan, LIU Changyou(), ZHANG Guorong, LÜ Jiahui, SONG Yuchen, JIE Wanqi   

  1. State Key Laboratory of Solidification Processing, School of Materials Science and Engineering, Northwestern Polytechnical University, Xi’an 710072, China
  • Received:2023-10-17 Revised:2023-11-21 Published:2024-04-20 Online:2023-12-04
  • Contact: LIU Changyou, associated professor. E-mail: lcy@nwpu.edu.cn
  • About author:ZHANG Tingting(2000-), female, Master candidate. E-mail: zhangtt@mail.nwpu.edu.cn
  • Supported by:
    Key Research and Development Program of Shaanxi Province(2021GY-202);National Natural Science Foundation of China(52072300);National Natural Science Foundation of China(61874089)

摘要:

Cr2+掺杂ZnSe纳米晶是一种重要的中红外材料, 核壳结构的ZnSe基半导体纳米晶表现出优异的光学、电学与催化性能。纳米晶的缺陷可以影响其性能, 如具有孪晶结构的纳米晶拥有更高的强度和硬度。为了提高掺杂纳米晶的综合性能, 本工作以可溶性Zn盐为Zn源, 以新制NaHSe溶液为Se源, 以Cr(AC)2为掺杂源, 通过两次水热过程制备了核壳结构Cr2+:ZnSe/ZnSe, 在氩气保护或高真空下分别于400和800 ℃烧结获得了室温下化学性质稳定的纳米晶。结构和形貌表征结果显示, 纳米晶尺寸主要集中在20~30 nm之间, 壳体厚度约为2.6 nm, 纳米晶具有层错缺陷, 并由此发展成为孪晶。分析可知孪晶面为(111), 相邻两晶面夹角为70.02°, 误差在±0.5°以内。随着样品结晶度提高, 孪晶密度增大, 表明释放晶格畸变能为层错和孪晶的形成提供驱动力, 孪晶的形核与长大符合位错诱导机制。XPS分析表明, Cr元素以+2价存在于纳米晶中; 反射光谱测试结果分析发现, 烧结的纳米晶在1775 nm附近存在吸收带, 表明所制纳米孪晶具有潜在的中红外发光性能。

关键词: Cr2+:ZnSe, 核壳结构, 纳米孪晶, 孪晶机制, 烧结

Abstract:

Cr2+ doped ZnSe nanocrystals are an important type of mid-infrared materials. ZnSe-based semiconductor nanocrystals with core-shell structure have shown excellent optical, electrical and catalytic properties. The defects of nanocrystals are one of the important factors affecting their properties. For example, nanocrystals with twinned structure have higher strength and hardness. In order to improve the comprehensive performance of doped nanocrystals, Cr2+:ZnSe/ZnSe nanocrystals with core-shell structure were prepared by two-step hydrothermal processes, using soluble Zn salt as Zn source, newly prepared NaHSe solution as Se source, and Cr(AC)2 as doping source, and chemically stable nanocrystals at room temperature were obtained by sintering at 400 and 800 ℃ under protection of argon or high vacuum, respectively. Their structural and morphological characterization results show that the nanocrystalline size is mainly concentrated in the range of 20-30 nm, the shell thickness is about 2.6 nm, and the nanocrystals have delamination defects, thus twins are developed. The analysis results show that the twin plane is (111), the angle between the adjacent two crystal planes is 70.02°± 0.5°. The twin density of the sample increases with the increase of the crystallinity, which indicates that release of lattice distortion energy leads to formation of delamination and twin. Meanwhile, the twin growth can be explained by dislocation induced nucleation-growth. XPS analysis shows that Cr elements with a valence of +2 exist in the nanocrystals, and the reflection spectroscopy test shows that nanocrystals have an absorption band around 1775 nm, indicating that the prepared nanocrystals with twins have a promising mid-infrared luminescent property.

Key words: Cr2+:ZnSe, core-shell structure, nanotwins, twinning mechanism, sintering

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