TY - JOUR
T1 - The Strain Effects and Interfacial Defects of Large ZnSe/ZnS Core/Shell Nanocrystals
AU - Long, Zhiwei
AU - Yang, Gaoling
AU - Shao, Ruiwen
AU - Chen, Zhuo
AU - Liu, Yang
AU - Liu, Ronghui
AU - Zhong, Haizheng
N1 - Publisher Copyright:
© 2023 Wiley-VCH GmbH.
PY - 2024/1/25
Y1 - 2024/1/25
N2 - The shell growth of large ZnSe/ZnS nanocrystals(is of great importance in the pursuit of pure-blue emitters for display applications, however, suffers from the challenges of spectral blue-shifts and reduced photoluminescence quantum yields. In this work, the ZnS shell growth on different-sized ZnSe cores is investigated. By controlling the reactivity of Zn and S precursors, the ZnS shell growth can be tuned from defect-related strain-released to defect-free strained mode, corresponding to the blue- and red-shifts of resultant nanocrystals respectively. The shape of strain-released ZnSe/ZnS nanocrystals can be kept nearly spherical during the shell growth, while the shape of strained nanocrystals evolutes from spherical into island-like after the critical thickness. Furthermore, the strain between ZnSe core and ZnS shell can convert the band alignment from type-I into type-II core/shell structure, resulting in red-shifts and improved quantum yield. By correlating the strain effects with interfacial defects, a strain-released shell growth model is proposed to obtain large ZnSe/ZnS nanocrystals with isotropic shell morphology.
AB - The shell growth of large ZnSe/ZnS nanocrystals(is of great importance in the pursuit of pure-blue emitters for display applications, however, suffers from the challenges of spectral blue-shifts and reduced photoluminescence quantum yields. In this work, the ZnS shell growth on different-sized ZnSe cores is investigated. By controlling the reactivity of Zn and S precursors, the ZnS shell growth can be tuned from defect-related strain-released to defect-free strained mode, corresponding to the blue- and red-shifts of resultant nanocrystals respectively. The shape of strain-released ZnSe/ZnS nanocrystals can be kept nearly spherical during the shell growth, while the shape of strained nanocrystals evolutes from spherical into island-like after the critical thickness. Furthermore, the strain between ZnSe core and ZnS shell can convert the band alignment from type-I into type-II core/shell structure, resulting in red-shifts and improved quantum yield. By correlating the strain effects with interfacial defects, a strain-released shell growth model is proposed to obtain large ZnSe/ZnS nanocrystals with isotropic shell morphology.
KW - ZnSe/ZnS nanocrystals
KW - blue emitters
KW - core–shell structures
KW - large size nanocrystals
KW - shell growth mechanism
UR - http://www.scopus.com/inward/record.url?scp=85170654441&partnerID=8YFLogxK
U2 - 10.1002/smll.202306602
DO - 10.1002/smll.202306602
M3 - Article
AN - SCOPUS:85170654441
SN - 1613-6810
VL - 20
JO - Small
JF - Small
IS - 4
M1 - 2306602
ER -