物理化学学报

所属专题: 金属卤化物钙钛矿光电材料和器件

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两步互扩散法制备高性能CsPbCl3薄膜紫外光电探测器

吴炯桦1,3, 李一明1,3, 石将建1, 吴会觉1, 罗艳红1,3,4, 李冬梅1,3,4, 孟庆波1,2,4   

  1. 1 中国科学院清洁能源前沿研究重点实验室, 北京新能源材料与器件重点实验室, 北京凝聚态物理国家研究中心, 中国科学院物理研究所, 北京 100190;
    2 中国科学院大学材料光电研究中心, 北京 100049;
    3 中国科学院大学物理学院, 北京 100049;
    4 松山湖材料实验室, 广东 东莞 523808
  • 收稿日期:2020-04-13 修回日期:2020-05-02 录用日期:2020-05-07 发布日期:2020-05-13
  • 通讯作者: 孟庆波
  • 基金资助:
    国家重点研究开发项目(2018YFB1500101),国家自然科学基金(11874402,51421002,51627803,91733301,51761145042,51872321)和中国科学院国际合作项目(112111KYSB20170089)资助

UV Photodetectors Based on High Quality CsPbCl3 Film Prepared by a Two-Step Diffusion Method

Jionghua Wu1,3, Yiming Li1,3, Jiangjian Shi1, Huijue Wu1, Yanhong Luo1,3,4, Dongmei Li1,3,4, Qingbo Meng1,2,4   

  1. 1 Key Laboratory for Renewable Energy(CAS), Beijing Key Laboratory for New Energy Materials and Devices, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences(CAS), Beijing 100190, P. R. China;
    2 Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, P. R. China;
    3 School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, P. R. China;
    4 Songshan Lake Materials Laboratory, Dongguan 523808, Guangdong Province, P. R. China
  • Received:2020-04-13 Revised:2020-05-02 Accepted:2020-05-07 Published:2020-05-13
  • Supported by:
    The project was supported by the National Key R&D Program of China (2018YFB1500101), the National Natural Science Foundation of China (11874402, 51421002, 51627803, 91733301, 51761145042, 51872321) and the International Partnership Program of Chinese Academy of Sciences (112111KYSB20170089).

摘要: 紫外光电探测器无论在军用和民用上都有着巨大的应用前景,CsPbCl3作为钙钛矿家族中形成能最大,化学性能稳定的成员,在可见光盲区的紫外光电探测器中有着很大潜在的应用价值。本文针对CsPbCl3薄膜难以制备的问题,发展了一种两步互扩散溶液法,通过控制前驱体PbCl2的形貌,成功地制备了CsPbCl3薄膜。利用扫描电镜、吸收光谱和X射线表征技术,证实了制备出的薄膜表面平整无孔洞、晶粒饱满和吸光度强。通过瞬态荧光和变激发光强的稳态荧光,揭示了薄膜具有载流子寿命长、缺陷态少等优异性能。最终构建出了响应度为0.75(A·W-1)的横向结构紫外光电探测器,为将来进一步发展高性能CsPbCl3薄膜紫外光电探测器奠定了基础。

关键词: CsPbCl3, 紫外光电探测器, 两步法, 钙钛矿薄膜, 高质量

Abstract: Visible-blind ultra-violet (UV) photodetectors have great application prospects in military and civilian fields. Hence, it is important to develop high-efficiency UV photodetectors. Perovskite materials have been widely applied in many fields, such as solar cells, light-emitting diodes, and photodetectors, owing to their excellent optical properties. The CsPbCl3 perovskite has a great potential in visible-blind UV photodetectors owing to its stable chemical properties and a suitable band gap. However, due to the extremely poor precursor solubility of CsPbCl3, it is difficult to find a suitable solvent to prepare CsPbCl3 films. In this study, we developed a two-step diffusion method to prepare CsPbCl3 films. PbCl2 and CsCl were dissolved in different solvents to overcome the solubility problem of CsPbCl3. First, the PbCl2 film was spin coated on a soda-lime glass. The CsCl solution was then continually dropwise spin-coated on the PbCl2 film to form the CsPbCl3 film. By controlling the morphology of PbCl2 through different annealing temperatures, the influence of different PbCl2 precursor films on microstructure of the CsPbCl3 film was investigated. The X-ray diffraction and scanning electron microscopy profiles of the PbCl2 precursor film and the CsPbCl3 film suggested that when the annealing temperature was too low, excess dimethyl sulfoxide (DMSO) remained in the PbCl2 precursor film, which hindered the transformation of CsPbCl3. However, when the annealing temperature was too high, voids appeared in the CsPbCl3 film due to excess DMSO volatilization, which caused pinholes in the CsPbCl3 film. Finally, a pinhole-free, smooth CsPbCl3 film with full grains was obtained when PbCl2 was annealed at 80℃. To the best of our knowledge, this is the first time a high-quality CsPbCl3 film with 1 μm grains was prepared using a two-step diffusion method. Photoelectrical characterizations, such as ultraviolet-visible absorption, steady-state photoluminescence (PL), and time-resolved PL characterizations, were studied to evaluate the quality of the film. The as-prepared CsPbCl3 film had strong UV absorption and PL intensity, and its longer PL lifetime indicated that the film had fewer defect states. Furthermore, a UV photodetector with a lateral structure based on the CsPbCl3 film was fabricated. The related electrical characterizations, such as current voltage curves, showed a good responsivity of 0.75 (A·W-1) and an outstanding detectivity of 7.8×1012 Jones, which are better than those of contemporary commercial photodetectors. The findings of this study show that a two-step diffusion method can be used to prepare CsPbCl3 films with better features and that it has a great potential in the development of UV photodetectors in the future.

Key words: CsPbCl3, Ultraviolet photodetector, Two-step method, Perovskite film, High quality

MSC2000: 

  • O646