Self-Assembly of CsPbBr₃ Perovskites in Micropatterned Polymeric Surfaces: Toward Luminescent Materials with Self-Cleaning Properties

Abstract

In this work, we present a series of porous, honeycomb-patterned polymer films containing CsPbBr 3 perovskite nanocrystals as light emitters prepared by the breath figure approach. Microscopy analysis of the topography and composition of the material evidence that the CsPbBr 3 nanocrystals are homogeneously distributed within the polymer matrix but preferably confined inside the pores due to the fabrication process. The optical properties of the CsPbBr 3 nanocrystals remain unaltered after the film formation, proving that they are stable inside the polystyrene matrix, which protects them from degradation by environmental factors. Moreover, these surfaces present highly hydrophobic behavior due to their high porosity and defined micropatterning, which is in agreement with the Cassie− Baxter model. This is evidenced by performing a proof-of-concept coating on top of 3D-printed LED lenses, conferring the material with self-cleaning properties, while the CsPbBr 3 nanocrystals embedded inside the polymeric matrix maintain their luminescent behavior.

Spray-driven halide exchange in solid-state CsPbX3 nanocrystal films

“…These characteristics make PNCs attractive for solidstate optoelectronics applications, becoming realistic building blocks for devices such as solar cells, lasers, and light-emitting diodes, fotodetectors, sensors, and functional coatings. [1][2][3][4][5][6]75 Typically, colloidal inorganic lead halide PNCs are synthesized by a chemical reaction between lead(II) halides and a cesium precursor in the presence of capping agents. 1 Since most semiconductor devices are in the solid state, these colloidal PNCs solutions must be processed into thin films by conventional deposition techniques.…”

Self-assembly of perovskite nanocrystals

“…Hydrophobic interactions between the tail parts of the alkyl ligands play a critical role in the self-assembly of the NCs by keeping the NCs at a specific distance. Interestingly, the interparticle spacing among these NCs was revealed to be 2 nm, which matches the lengths of both OAm and OA [92,93].…”