Electrowetting‐Induced Morphological Evolution of Metal‐Organic Inverse Opals toward a Water‐Lithography Approach

This paper presents a unique morphological evolution of metal‐organic inverse opals (Pb(NO 3 ) 2 ‐poly(St‐MMA‐AA)) subjected to an electrowetting process. The morphology of the building blocks changes from interconnected pores to separated hollow spheres during the electrowetting process, accompanied by an unusual blue‐shift of the stopband position and the decreased wettability of the film. This morphology evolution is attributed to the simultaneous collapse/reconstruction of the metal‐organic frame owing to the partial dissolution of the metal salt and the interfacial assembly of the metal‐organic coordination around the skeleton. The adjustable morphology can be developed as a novel and simple water‐lithography approach for the creation of the photonic crystal pattern.