Centre Énergie Matériaux Télécommunications, Institut National de la Recherche Scientifique, Varennes, Québec J3X 1S2, Canada.
State Key Laboratory of Bo-Fibers and Eco-Textiles and College of Physics, Qingdao University, Qingdao, PR China.
Nanoscale. 2019 Nov 7;11(41):19529-19535. doi: 10.1039/c9nr06110j. Epub 2019 Oct 1.
Heterostructured quantum dots (hetero-QDs) have outstanding optical properties and chemical/photostability, which make them promising building blocks for use in various optoelectronic devices. Here, CuInSeS/CdSeS/CdS hetero-QDs were synthesized through a facile two-step method. Their particle size, three-dimensional (3D) shapes and the epitaxial relationship between the CuInSeS/CdSeS core and CdS shell were investigated by high-resolution transmission electron microscopy (HRTEM). Our investigation proves that the as-synthesized hetero-QDs have a regular tetrahedron 3D shape with four {111} crystal facets. The epitaxial relationship between the CuInSeS/CdSeS core and CdS shell is determined to be [110]//[110], {112}//{111}. In situ HRTEM observations show that the screw dislocation inside the hetero-QDs can be efficiently repaired using e-beam irradiation. These results may help in designing hetero-QDs with high-quality interfaces and identifying the strategies for synthesizing defect-free hetero-QDs.
具有不同结构的量子点（hetero-QDs）具有出色的光学性质和化学/光稳定性，这使它们成为各种光电设备的有前途的构建块。在这里，通过简便的两步法合成了 CuInSeS/CdSeS/CdS 异质量子点。通过高分辨率透射电子显微镜（HRTEM）研究了它们的粒径、三维（3D）形状以及 CuInSeS/CdSeS 核和 CdS 壳之间的外延关系。我们的研究证明，所合成的异质量子点具有具有四个 {111} 晶面的规则四面体 3D 形状。CuInSeS/CdSeS 核和 CdS 壳之间的外延关系确定为 [110]//[110]，{112}//{111}。原位 HRTEM 观察表明，电子束辐照可以有效地修复异质量子点内的螺旋位错。这些结果可能有助于设计具有高质量界面的异质量子点，并确定合成无缺陷异质量子点的策略。
