(Invited) Nanopatterned Perovskite Films for High Performance Photo-Electronics

Abstract

Ordered nanostructured crystals of thin perovskites films are of great interest to researchers because of the dimensional-dependence of their photoelectronic properties for developing the perovskites with novel properties [1]. In this presentation, both top-down and bottom-up approaches for fabricating nanostructured perovskite films are demonstrated. First, a variety of micro/nanopatterns of a perovskite film are fabricated by either micro/nano-imprinting or transfer-printing a thin spin-coated precursor film in soft-gel state with a topographically pre-patterned polymer mold, followed by thermal treatment for complete conversion of the precursor film to a perovskite one [2]. Second, we also demonstrate a simple and robust route, involving the controlled crystallization of the perovskites templated with a self-assembled block copolymer (BCP), for fabricating nanopatterned perovskite films with various shapes and nanodomain sizes [3]. When the precursor ion solution of a perovskite and poly(styrene)-block-poly(2-vinylpyridine) (PS-b-P2VP) was spin-coated on the substrate, a nanostructured BCP was developed by microphase separation. Spontaneous crystallization of the precursor ions preferentially coordinated with the P2VP domains yielded ordered nanocrystals with various nanostructures. The nanopatterned perovskites showed significantly enhanced photoluminescence (PL) with high resistance to both humidity and heat due to geometrically confining crystals in and passivation with the P2VP chains. Finally, we demonstrate that the perovskite crystals are more precisely controlled by the combination of the BCP self-assembly with top-down nanoimprinting.