Effect of interface alloying and band-alignment on the Auger recombination of heteronanocrystals

TL;DR

This study numerically investigates how interface alloying and band alignment influence Auger recombination in heteronanocrystals, revealing suppression strategies through interface smoothness and type-II structures to enhance nanocrystal performance.

Contribution

It demonstrates that interface alloying and band alignment can significantly suppress Auger recombination in heteronanocrystals, providing design insights for improved nanocrystal efficiency.

Findings

Smooth interfaces suppress Auger recombination, sensitive to core size.

Type-II structures further reduce Auger processes, especially with electron confinement.

Extended interface alloying and wide band gap facilitate realization of 'magic' sizes with negligible Auger recombination.

Abstract

We report a numerical study of the effect of interface alloying and band-alignment on the Auger recombination processes of core/shell nanocrystals. Numerical calculations are carried out using a two-band Kane Hamiltonian. Smooth interfaces are found to suppress Auger recombination, the strength of the suppression being very sensitive to the core size. The use of type-II structures constitutes an additional source of suppression, especially when the shell confines electrons rather than holes. We show that "magic" sizes leading to negligible Auger recombination [Cragg and Efros, Nano Letters 10 (2010) 313] should be easier to realize experimentally in nanocrystals with extended interface alloying and wide band gap.