Pre-Shell Protection Suppresses Facet-Selective Core Digestion in InP Quantum Dots for High-Yield and Uniform Core/Shell Structures

Indium phosphide (InP) quantum dots (QDs) are leading cadmium-free alternatives for advanced display technologies, offering wide emission tunability and environmental compliance. However, achieving a high production yield and size uniformity remains challenging. Here we identify a previously overlooked phenomenon, i.e., facet-selective dissolution of InP cores ("core digestion") during the high-temperature ramping stage in zinc oleate media. This process reduces the number of cores, thereby broadening the core size distribution and disturbing the subsequent shell growth conditions. We introduce a preshell protection strategy that stabilizes the InP core surface before ZnSe/ZnS shell growth, effectively suppressing core digestion. As a result, the obtained core/shell QDs exhibit an enhanced particle yield, improved size uniformity, and superior optical performance. This work reveals a degradation pathway in InP synthesis and provides a practical route to scalable, high-quality QDs for display applications.