Direct Optical Patterning of Colloidal Nanocrystals

Colloidal nanocrystals (NCs) have emerged as a diverse class of materials with tunable composition, size, shape, and surface chemistry. From their facile syntheses to their unique optoelectronic properties, these solution-processed NCs are a promising alternative to materials grown as bulk crystals or by vapor-phase methods. However, the use of NCs in real-world devices is often held back by challenges in depositing them as a patterned two-dimensional layer. Alternative approaches to patterning colloidal NCs need to be established to aid the transition from individual devices to integrated optoelectronic circuits, multi-color NC displays, and nanophotonic devices. This talk will focus on the development of photo-chemical methods that enable direct optical lithography of colloidal nanocrystals. We will discuss various light-sensitive ligands and their suitability for patterning various NCs including lead halide perovskite NCs, semiconducting quantum dots, metal oxide nanoparticles, and lanthanide-doped upconverting NCs. We will show that this patterning approach preserves many of the desirable properties of the NCs, such as high photoluminescence, good charge transport, and high refractive index. Ultimately, this work aims to expediate the implementation of colloidal NCs in a broader range of functional devices.