Mulder Jence T, Kirkwood Nicholas, De Trizio Luca, Li Chen, Bals Sara, Manna Liberato, Houtepen Arjan J
Optoelectronic Materials Section, Faculty of Applied Sciences, Delft University of Technology, Van der Maasweg 9, 2629HZ Delft, The Netherlands.
Department of Nanochemistry, Istituto Italiano di Tecnologia (IIT), Via Morego 30, 16163 Genova, Italy.
ACS Appl Nano Mater. 2020 Apr 24;3(4):3859-3867. doi: 10.1021/acsanm.0c00583. Epub 2020 Mar 16.
Indium phosphide quantum dots (QDs) have drawn attention as alternatives to cadmium- and lead-based QDs that are currently used as phosphors in lamps and displays. The main drawbacks of InP QDs are, in general, a lower photoluminescence quantum yield (PLQY), a decreased color purity, and poor chemical stability. In this research, we attempted to increase the PLQY and stability of indium phosphide QDs by developing lattice matched InP/MgSe core-shell nanoheterostructures. The choice of MgSe comes from the fact that, in theory, it has a near-perfect lattice match with InP, provided MgSe is grown in the zinc blende crystal structure, which can be achieved by alloying with zinc. To retain lattice matching, we used Zn in both the core and shell and we fabricated InZnP/Zn Mg Se core/shell QDs. To identify the most suitable conditions for the shell growth, we first developed a synthesis route to Zn Mg Se nanocrystals (NCs) wherein Mg is effectively incorporated. Our optimized procedure was employed for the successful growth of Zn Mg Se shells around In(Zn)P QDs. The corresponding core/shell systems exhibit PLQYs higher than those of the starting In(Zn)P QDs and, more importantly, a higher color purity upon increasing the Mg content. The results are discussed in the context of a reduced density of interface states upon using better lattice matched Zn Mg Se shells.
磷化铟量子点（QDs）作为镉基和铅基量子点的替代品受到关注，镉基和铅基量子点目前用作灯具和显示器中的磷光体。一般来说，磷化铟量子点的主要缺点是光致发光量子产率（PLQY）较低、色纯度降低以及化学稳定性较差。在本研究中，我们试图通过开发晶格匹配的InP/MgSe核壳纳米异质结构来提高磷化铟量子点的PLQY和稳定性。选择MgSe是因为理论上，如果MgSe以闪锌矿晶体结构生长，它与InP具有近乎完美的晶格匹配，这可以通过与锌合金化来实现。为了保持晶格匹配，我们在核和壳中都使用了锌，并制备了InZnP/ZnMgSe核/壳量子点。为了确定壳生长的最合适条件，我们首先开发了一种合成路线来制备有效掺入Mg的ZnMgSe纳米晶体（NCs）。我们采用优化后的程序成功地在In(Zn)P量子点周围生长了ZnMgSe壳。相应的核/壳系统表现出比起始In(Zn)P量子点更高的PLQY，更重要的是，随着Mg含量的增加，色纯度更高。在使用晶格匹配更好的ZnMgSe壳时，界面态密度降低的背景下讨论了这些结果。
