Developing Lattice Matched ZnMgSe Shells on InZnP Quantum Dots for Phosphor Applications

Abstract

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 x Mg1–x Se core/shell QDs. To identify the most suitable conditions for the shell growth, we first developed a synthesis route to Zn x Mg1–x Se nanocrystals (NCs) wherein Mg is effectively incorporated. Our optimized procedure was employed for the successful growth of Zn x Mg1–x 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 x Mg1–x Se shells.

Synergistic Effect of Halogen Ions and Shelling Temperature on Anion Exchange Induced Interfacial Restructuring for Highly Efficient Blue Emissive InP/ZnS Quantum Dots

“…To improve their performance, several common methods have been reported including HF etching, [13,31,32] metal salts post-treatment, [22,33,34] and core/ shell structure. [13,[35][36][37][38] Among them, core/shell structure is one of the most effective and extensive strategies, and zinc sulfide (ZnS) is adopted as shell owing to its wide band gap generally, which could passivate the surface defects and reduce electron delocalization effectively. However, the lattice mismatch of 7.7% between InP core and ZnS shell causes nonradiative recombination of excitons at the interface.…”

Robust direct Z-scheme exciton transfer dynamics by architecting 3D BiOI MF-supported non-stoichiometric Cu0.75In0.25S NC nanocomposite for co-catalyst-free photocatalytic hydrogen evolution

“…Furthermore, the role of capping agent (TGA) has a great influence in the synthesis of non-stoichiometric ternary CIS NC as surface ligands enhancing the chemical stability of the ternary NC by preventing agglomeration during the formation of binary NCs. 32 Crystallography, morphological, optical and electrical properties of the prepared, neat and binary composites are well characterized. Further, the catalytic performance of the designed photocatalysts was tested toward the water reduction reaction under ambient conditions.…”

Mg substitution in zinc selenide: Enhanced optoelectronic and thermoelectric performance

“…Additionally, in a recent research, Jence T. Mulder et al uses Zn x Mg 1− x Se shells around Quantum dots (QD) In(Zn)P with Mg content. The inclusion of Mg in the shell results in narrower emission characteristics and which may be of great interest in the production of high quality phosphors for optoelectronic applications [14].…”