Self-assembly of perovskite nanoplates in colloidal suspensions

Autor(es)

Moral, Raphael F. ; Malfatti-Gasperini, Antonio A. ; Bonato, Luiz G. ; Vale, Brener R. C. ; Fonseca, Andre F. V. ; Padilha, Lazaro A. ; Oliveira, Cristiano L. P. ; Nogueira, Ana F.

• Tipo de documento: Artigo Científico
• Fonte: MATERIALS HORIZONS; v. N/A, p. 13-pg., 2023-10-05.

Resumo

In recent years, perovskite nanocrystal superlattices have been reported with collective optical phenomena, offering a promising platform for both fundamental science studies and device engineering. In this same avenue, superlattices of perovskite nanoplates can be easily prepared on different substrates, and they too present an ensemble optical response. However, the self-assembly and optical properties of these aggregates in solvents have not been reported to date. Here, we report on the conditions for this self-assembly to occur and show a simple strategy to induce the formation of these nanoplate stacks in suspension in different organic solvents. We combined wide- and small-angle X-ray scattering and scanning transmission electron microscopy to evaluate CsPbBr3 and CsPbI3 perovskite nanoplates with different thickness distributions. We observed the formation of these stacks by changing the concentration of nanoplates and the viscosity of the colloidal suspensions, without the need for antisolvent addition. We found that, in hexane, the concentration for the formation of the stacks is rather high and approximately 80 mg mL-1. In contrast, in decane, dodecane, and hexadecane, we observe a much easier self-assembly of the nanoplates, presenting a clear correlation between the degree of aggregation and viscosity. We, then, discuss the impact of the self-assembly of perovskite nanoplates on Forster resonant energy transfer. Our predictions suggest an energy transfer efficiency higher than 50% for all the donor-acceptor systems evaluated. In particular, we demonstrate how the aggregation of these particles in hexadecane induces FRET for CsPbBr3 nanowires. For the n = 2 nanowires (donor) to the n = 3 nanowires (acceptor), the FRET rate was found to be 4.1 ns-1, with an efficiency of 56%, in agreement with our own predictions. We show a monotonic increase in the degree of aggregation of perovskite nanoplates with the viscosity of the solvent. We use SAXS to show the stacking patterns. It is a novel approach to explore the self-assembly of perovskite nanoplates. (AU)

• Processo FAPESP: 18/15574-6 - Espectroscopia avançada de nanomateriais: de suspensões coloidais à partícula única
• Beneficiário: Lázaro Aurélio Padilha Junior
• Modalidade de apoio: Auxílio à Pesquisa - Jovens Pesquisadores - Fase 2
• Processo FAPESP: 21/13262-0 - Síntese de Novas Nanoestruturas de Perovskita
• Beneficiário: Luiz Gustavo Bonato
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 17/11986-5 - Geração e Armazenamento de Novas Energias: trazendo desenvolvimento tecnológico para o país
• Beneficiário: Ana Flávia Nogueira
• Modalidade de apoio: Auxílio à Pesquisa - Programa Centros de Pesquisa em Engenharia
• Processo FAPESP: 19/25765-6 - Experimentos in situ com SAXS e WAXS em síncrotron para estudar reações e mecanismos de formação de (nano)materiais de halogenetos de chumbo
• Beneficiário: Raphael Fernando Moral
• Modalidade de apoio: Bolsas no Brasil - Doutorado