Doping Strategy Enabling CsPbBrI2 Perovskite Quantum Dot-Photoresist Compatible Blending with High Stability for Ultra-Simplified Photolithography

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 CsPbBrI 2 QDs is paramount to enable their direct mixing with PR for subsequent lithographic processing. Herein, a B-site-doped CsPbBrI 2 QD is designed by introducing Sr 2 ⁺. This doping enhances the lattice stability and partially repairs surface defects. The Sr-doped CsPbBrI 2 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 CsPbBrI 2 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 CsPbBrI 2 QDs and the commercial PR synergistically overcome compatibility barriers, facilitating simple and efficient photolithographic patterning.