Dual-Solvent Screening for Nondestructive In-Situ Optical Patterning of CsPbX3 QDs/PMMA

Perovskite quantum dot (PQD)-polymer composites are widely pursued for display devices due to their excellent film-forming capacity, low cost, and favorable process compatibility. However, interfacial incompatibility between PQDs and polymers from mismatched surface chemistry triggers PQD aggregation and severe photoluminescence quenching, hindering microdisplay applications. Herein, a dual-solvent screening strategy is demonstrated for I-184-initiated crosslinked PQD-PMMA photoresists to balance solubility and lead-ion coordination strength. Undesired lead-solvent intermediate formation and residual solvent accumulation are suppressed to homogenize PQD dispersion and preserve optical performance. The 20 μm green patterned film retains 93% of the initial photoluminescence quantum yield with no photoluminescence peak shift and a narrow full width at half-maximum of 16.6 nm. The PQD pattern presents sharp pixel edges, 7.10% critical dimension deviation, 97.1% replication rate, and intersection over union of 0.92. This solvent engineering enables the revitalization of conventional polymers and addresses bottlenecks in photolithographic patterning of PQD-polymer composites.