Doping Strategy Enabling CsPbBrI₂ Perovskite Quantum Dot-Photoresist Compatible Blending with High Stability for...

Incorporating perovskite quantum dots (PQDs) into photoresist (PR) and utilizing mature photolithography processes is an optimal strategies for achieving patterning, perfectly aligning with the requirements for large-scale manufacturing. Consequently, enhancing the intrinsic stability of the red-emitting CsPbBrI₂ QDs is paramount to enable their direct mixing with PR for subsequent lithographic processing. Herein, a B-site-doped CsPbBrI₂ QD is designed by introducing Sr²⁺. This doping enhances the lattice stability and partially repairs surface defects. The Sr-doped CsPbBrI₂ QDs solution maintains stability for 30 days, retaining 93.7% of its initial photoluminescence (PL) intensity with a PL peak barely shift, while the films show enhanced thermal tolerance. Owing to the high stability, the Sr-doped CsPbBrI₂ QDs are mixed with commercial PR, and the blend maintained a photoluminescence quantum yield (PLQY) of 61%. Photolithographic patterned films achieve the minimum feature size of 88.39 µm with better uniformity and luminescence intensity. Encapsulated within the PR matrix, the QD-PR films confer exceptional water stability, retaining strong luminescence even after 48 h immersion, and resistance to polar solvents. Sr-doped CsPbBrI₂ QDs and the commercial PR synergistically overcome compatibility barriers, facilitating simple and efficient photolithographic patterning.