High-Resolution Quantum Dot Photopatterning via Interference Lithography Assisted Microstamping

We present novel photopatterning approaches based on near-field and far-field interference lithography techniques that yield highly uniform high-resolution large-area face-profile and edge-profile photopatterns. The near-field interference methods utilize a phase-shift mask while the far-field method uses two-beam interference. These interference-based techniques yield photopatterns with minimum feature sizes near 500 nm, which matches the current resolution of photopatterning. Furthermore, these interference techniques drastically increase the patternable area (up to cm2) and the throughput (increases of up to 3 orders of magnitude) while maintaining pattern uniformity. Furthermore, these strategies use easy-to-handle reusable photomasks or no masks at all and address the major constraints associated with obtaining high resolution without compromising throughput that have often limited the applicability of traditional photopatterning. Finally, all approaches can be applied multiple times on the same film area to yield ultradense multilevel intensity contrast photopatterns that are very difficult to obtain using traditional strategies. These interference-based exposure techniques represent a paradigm shift in the field of photopatterning and will be valuable for applications that require uniform high-resolution patterns over large areas, such as photosensors, anticounterfeiting labels, and virtual displays.