Minimizing Defects in Blue‐Emitting ZnSeTe Quantum Dots Using ZnF 2 Throughout Core and Shell Growth

ZnSeTe quantum dots (QDs) are attractive candidates for next-generation blue-light display applications. However, their optical performance is often compromised by surface and structural defects that introduce nonradiative recombination pathways. Although various synthetic strategies-such as post-synthetic surface passivation and hydrofluoric acid (HF) treatment-have been explored to mitigate these defects, they typically involve complex protocols or hazardous reagent handling. Here, we present a facile and scalable synthetic strategy for producing high-quality blue-emitting ZnSeTe QDs by employing ZnF2 as a multifunctional precursor throughout both core and shell growth. ZnF2 enhances optical properties (i) by suppressing crystal and surface defects through sustained in situ HF generation, and (ii) by functioning simultaneously as Z-type and X-type surface ligands for effective surface passivation. This approach yields ZnSeTe QDs with a photoluminescence quantum yield (PLQY) approaching unity (0.98), accomplished by suppressing both surface and lattice defects to minimize nonradiative recombination pathways. Our facile methodology provides a safe and effective route toward cadmium-free, high-performance blue-emitting QDs for optoelectronic applications.