Direct Optical Patterning

​To fully exploit various functionalities of colloidal inorganic nanocrystals, it is important to selectively deposit the nanocrystal arrays onto the desired locations of thin-film devices or integrated (opto)electronic circuitry by using precise material-adapted patterning methods.

 

Direct Optical Patterning is an alternative "photoresist-free" optical patterning method for colloidal inorganic nanocrystals. DOLFIN can overcome the limitations of traditional photolithography for solution processing such as the use of photoresists and nonuniform pattern profiles, however, its application to light-emissive nanocrystals requires advanced patterning methods that do not harm the optical, electrical, and structural characteristics of the nanocrystals. Our group works on the development of advanced direct optical methods for various nanomaterials that can be practically adopted by industry.

 

Direct optical patterning can be classified according to the underlying mechanism that modulates NC solubility: in-situ ligand exchange, ligand cleavage, and ligand crosslinking. Our research team has established unique patterning techniques for each of these mechanisms. More recently, we have developed advanced patterning strategies that not only suppress post-patterning luminescence loss but also enhance device performance, improve ink stability, and enable defect passivation.