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Identification of core/shell structure in Cd‐Zn‐Se QDs inside silicate glasses using 3D elemental distribution analysis
Author(s) -
Lee Hojeong,
Park Won Ji,
Han Jong Chan,
Park ChanGyeong,
Heo Jong
Publication year - 2021
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/jace.17436
Subject(s) - atom probe , materials science , quantum dot , transmission electron microscopy , irradiation , silicate , analytical chemistry (journal) , core (optical fiber) , chemical engineering , nanotechnology , chemistry , composite material , physics , chromatography , nuclear physics , engineering
Core‐shell structure in Cd‐Zn‐Se quantum dots (QDs) precipitated in the silicate glass matrix by continuous wave laser (λ = 532 nm) were demonstrated using transmission electron microscopy (TEM) and local electrode atom probe (LEAP) tomography. TEM images of the QDs in glasses after 60 min of irradiation at 9 W/cm 2 show two portions with different contrasts, and diameters of 5.97 and 22.49 nm, respectively; 3D elemental distribution in these glasses from LEAP tomography shows areas of high Zn concentration near the CdSe QDs. Iso‐concentration images obtained using visualization software show that Cd‐rich clusters were not completely covered by the Zn‐rich shells in the glass after 15 min irradiation that resulted emission due to the surface defects of CdSe QDs. As the irradiation time increased to 60 min, the Zn‐rich cluster gradually surrounded the Cd‐rich core to form shells that eliminated the surface defects. During laser irradiation, CdSe QDs precipitated first due to the high degree of supersaturation of Cd and Se followed by the sequential incorporation of Zn on the Cd‐rich QDs forming shells.