Ultra-high-resolution nondestructive photolithography of quantum dots enabled by photo-shield crosslinker

Abstract

Direct photolithography of colloidal quantum dots (QDs) has emerged as a pivotal technology for next-generation optoelectronics due to its exceptional patterning potential and broad material compatibility. While short-wavelength ultraviolet (e.g., deep ultraviolet [DUV]) is critical for minimizing diffraction effects, it induces severe photo-damage to QDs and undesirable side reactions. To date, no existing strategy has successfully addressed the incompatibility between QDs and DUV to achieve submicron-scale patterning while preserving optoelectronic properties. Here, we develop a photo-shield photolithography strategy implemented through rationally designed acetophenone-based crosslinkers, which enables efficient DUV shield to QDs and precise photo-crosslinking. Based on this strategy, a record-breaking spatial resolution (>18000 PPI, pixel size ≈ 0.55 μm) is demonstrated with fully maintained QD structure and photoluminescent properties. The fabricated light-emitting diode prototype achieves a record peak external quantum efficiency of ∼ 20.3 %. This strategy decouples resolution scaling from material damage, establishing the first nondestructive DUV photolithography framework of QDs, and creating new opportunities for QD-based ultra-high-resolution information displays and other optoelectronic platforms.