Novel synthesis of Mn: ZnSe@ZnS core-shell quantum dots based on photoinduced fluorescence enhancement

Qiuju Chen; Zizhi Huang; Qiong Wang; Yunchu Hu; Hao Tang; Ruizhi Wen; Wenlei Wang

doi:10.1016/j.saa.2020.119099

Novel synthesis of Mn: ZnSe@ZnS core-shell quantum dots based on photoinduced fluorescence enhancement

Spectrochim Acta A Mol Biomol Spectrosc. 2021 Mar 5:248:119099. doi: 10.1016/j.saa.2020.119099. Epub 2020 Oct 24.

Authors

Qiuju Chen¹, Zizhi Huang¹, Qiong Wang², Yunchu Hu¹, Hao Tang³, Ruizhi Wen¹, Wenlei Wang¹

Affiliations

¹ College of Science, Central South University of Forestry and Technology, Changsha 410004, China.
² College of Science, Central South University of Forestry and Technology, Changsha 410004, China; Ministry of Education Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research, College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081, China. Electronic address: wangqiong@csuft.edu.cn.
³ Ministry of Education Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research, College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081, China.

PMID: 33214102
DOI: 10.1016/j.saa.2020.119099

Abstract

A novel Type-I Mn: ZnSe@ZnS core-shell quantum dots (QDs) was reported through a two-step procedure by using low-cost inorganic salts and naturalbiomacromolecule as raw materials. Based on a designed structure of L-cysteine-capped Mn: ZnSe QDs in aqueous media with the controllable surface, Mn: ZnSe@ZnS core-shell QDs were formed due to photoactive ions and defect curing under continuous constant light. The influences of experimental variables, including synthesis conditions of Mn: ZnSe QDs, different types and affecting factors of photo irradiation had been systematically investigated. Under the effect of photoinduced fluorescence enhancement, the photoluminescence (PL) intensity increases significantly by about 5-10 times after 1-3 h of UV irradiation. The position of the fluorescence peak was red-shifted by about 17 nm, emitting orange-red fluorescence. The photoluminescence quantum yield (PL QY) was markedly improved (up to 35%). The structure and morphology of Mn: ZnSe@ZnS core-shell QDs were also confirmed by Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and energy-dispersive X-ray spectroscopy (EDS) in detail. The mechanism of photoinduced fluorescence enhancement was attributed to L-cysteine allowed to release S^2- to form a ZnS shell, and the passivated surface non-radiative relaxation centers of Mn: ZnSe@ZnS QDs was successfully synthesized with highuniform size, excellent photoluminescence performance, and good stability, all ofwhichmakethemgood potential candidates for white LEDs, and biological labels.

Keywords: Core–shell; Mn: ZnSe@ZnS; Photoinduced fluorescence enhancement; UV irradiation.