Mechanism of carrier localization in doped perovskite nanocrystals for bright emission

TL;DR

This study reveals how manganese doping enhances exciton localization and emission rates in perovskite nanocrystals, offering a new approach to improve their luminescence efficiency for lighting applications.

Contribution

It demonstrates that Mn doping increases exciton localization and radiative recombination rates, supported by experimental spectroscopy and ab initio calculations, revealing a fundamental mechanism for luminescence enhancement.

Findings

Doping increases intrinsic excitonic radiative recombination rate.

Mn dopants induce lattice periodicity breaking, enhancing exciton localization.

Enhanced emission rates improve luminescence efficiency in perovskite nanocrystals.

Abstract

Nanocrystals based on metal-halide perovskites offer a promising material platform for highly efficient lighting. Using transient optical spectroscopy, we study excitation recombination dynamics in manganese-doped CsPb(Cl,Br)3 perovskite nanocrystals. We find an increase in the intrinsic excitonic radiative recombination rate upon doping, which is typically a challenging material property to tailor. Supported by ab initio calculations, we can attribute the enhanced emission rates to increased exciton localization through lattice periodicity breaking from Mn dopants, which increases exciton effective masses and overlap of electron and hole wavefunctions and thus the oscillator strength. Our report of a fundamental strategy for improving luminescence efficiencies in perovskite nanocrystals will be valuable for maximizing efficiencies in light-emitting applications.