Energy Transfer in Stability-Optimized Perovskite Nanocrystals

TL;DR

This study demonstrates efficient energy transfer in stability-enhanced perovskite nanocrystals encapsulated in copolymer micelles, balancing FRET efficiency and environmental stability for improved optoelectronic devices.

Contribution

It introduces a method to encapsulate perovskite NCs in tunable micelles that maintain high FRET efficiency while improving stability under ambient conditions.

Findings

FRET efficiencies up to 73.6% between NCs and NPLs.

Micelle size influences FRET efficiency and protection.

Optimal shell thickness balances energy transfer and stability.

Abstract

Outstanding optoelectronic properties and a facile synthesis render halide perovskite nanocrystals (NCs) a promising material for nanostructure-based devices. However, the commercialization is hindered mainly by the lack of NC stability under ambient conditions and inefficient charge carrier injection. Here, we investigate solutions to both problems, employing methylammonium lead bromide (MAPbBr_3) NCs encapsulated in diblock copolymer core-shell micelles of tunable size. We confirm that the shell does not prohibit energy transfer, as FRET efficiencies between these NCs and 2D CsPbBr_3 nanoplatelets (NPLs) reach 73.6%. This value strongly correlates to the micelle size, with thicker shells displaying significantly reduced FRET efficiencies. Those high efficiencies come with a price, as the thinnest shells protect the encapsulated NCs less from environmentally induced degradation. Finding the sweet spot between efficiency and protection could lead to the realization of tailored energy funnels with enhanced carrier densities for high-power perovskite NC-based optoelectronic applications.