ZnO 量子点多重混合自陷域激子发光与应用

打开文本图片集

中图分类号：O482. 31 文献标识码： ADOI：10. 37188/CJL. 20240344 CSTR：32170. 14. CJL. 2024034

ZnO QDs with Multiple Hybrid Self-trapping Excitons Emission and Application

GAO Mengdi，CAO Qing，SONG Shiyu*，LIU Kaikai*，SHAN Chongxin （Key Laboratory of Materials Physics，Ministry of Education，School of Physics（The light of the Central Plains Laboratory）， Zhengzhou University，Zhengzhou ，China） * Corresponding Authors，E-mail：sysong@zzu. edu. cn；liukaikai@zzu. edu. cn

Abstract：The emission of ZnO in the visible light region has a long and complicated history. In previous studies， researchers have attributed the emissions in the visible light region to the existence of impurities or structural defects （such as oxygen vacancies，zinc vacancies，zinc interstitials，surface states）. However，there are still certain differ⁃ ences. For quantum dots（QDs）with good crystallinity and high luminous efficiency，it is contradictory to attribute their emission mechanism in the visible light region to the defect model. This paper proposes a multiple bright singlet/ triplet hybrid self-trapped exciton emission model for ZnO QDs，whose luminescence range covers from 400 nm to 700nm . The Photoluminescence quantum yield（PLQY）of singlet exciton and triplet exciton emission are 45.56% and 22. 44% ，respectively. Thanks to their good transparency and bright triplet excitons，we have explored the X-ray detection imaging by ZnO QDs as scintillator. The lowest detection limit of the ZnO QD scintillator for X -ray is as low as 64.89nGy/s ，which is lower than the dose required for X-ray medical imaging. This work puts forward a new mod⁃ el for visible emission in ZnO QDs，demonstrating a new type of transparent scintillator and their potential applica⁃ tion in X-ray imaging.

Key words：ZnO QDs；self-trapped excitons；singlet/triplet；X-ray imaging

1 引 言

自陷域激子发光材料在固态照明、太阳能电池、X 射线探测成像等领域已得到广泛的研究[1-7]。（剩余17523字）