Direct Optical Lithography of Intrinsically Stretchable Colloidal Emissive Nanocrystals

Abstract

Realizing high-resolution stretchable displays requires emissive materials that combine photopatternability with intrinsic stretchability. In colloidal nanocrystal films, however, the network formation needed for precise patterning often restricts molecular mobility, creating a fundamental trade-off with mechanical compliance. Here, we address this challenge using a benzophenone-based dual-crosslinker strategy that forms an elastomeric nanocrystal network. The tetrafunctional small-molecule crosslinker promotes efficient photopatterning, whereas the benzophenone-terminated polybutadiene crosslinker provides mechanical compliance. By tuning the crosslinker composition, the dual-crosslinking system enables direct optical patterning with line widths down to 2 μm and crack-free deformation up to 36% uniaxial strain. Both perovskite and InP-based nanocrystals largely retain their photoluminescence after processing, while the dual-crosslinking platform enables multicolor patterning and transfer to elastomeric substrates. QLEDs incorporating strained emissive layers maintain more than 90% of the maximum luminance of their unstretched counterparts. This dual-crosslinker design offers a general route to intrinsically stretchable, directly photopatternable colloidal nanocrystal emission layers.