Acrylic Acid–Enabled Indium Phosphide‐Based Quantum Dot Inks for High‑Resolution Electrohydrodynamic Patterning

To enable printable, cadmium‑free quantum dots (QDs) for high‑resolution micropatterned devices, we report an acrylic acid (AA)‑mediated strategy that integrates QD surface passivation with ink engineering. As a multifunctional ligand, the AA molecule can undergo protonation‑driven etching, which removes surface defects; amidation, which yields strong coordination to surface atoms; and vinyl‑enabled in situ oligomerization/cross‐linking, which concurrently forms a low‐molecular‐weight acrylic oligomer network during ZnSe shell growth. This synergistic treatment substantially reduces trap densities on InP core QD surfaces and markedly improves optical stability. The resulting InP/ZnSe emitters exhibit over twofold enhancement in photoluminescence quantum yield (PLQY) relative to controls and excellent photostability. Crucially, the in situ‐formed acrylic oligomer matrix tailors the ink's viscoelasticity and homogeneity in a printing‐relevant state, suppressing coffee‑ring effects without requiring any polymer additives and enabling direct electrohydrodynamic (EHD) printing of high‑resolution micropatterns. This integrated strategy provides a practical pathway to scalable, high‐performance InP QD‐based macroscopic printing.