Core/Shell Magic-Sized Semiconductor Nanocrystals

29 June 2021, Version 1
This content is a preprint and has not undergone peer review at the time of posting.

Abstract

Magic-sized semiconductor nanocrystals (MSNCs) grow via discrete jumps between specific sizes. Despite their potential to offer atomically precise structures, their use has been limited by poor stability and trap-dominated photoluminescence. Recently, syntheses have been reported that produce CdSe MSNCs over a larger size series. We exploit such particles and demonstrate a method to grow shells on CdSe MSNC cores. Thin CdS shells lead to dramatic improvements in the emissive properties of the MSNCs, narrowing their fluorescence linewidths, enhancing photoluminescence quantum yields, and eliminating trap emission. While thicker CdS shells lead to decreased performance, CdxZn1-xS alloyed shells maintain efficient and narrow fluorescence lines. These alloyed core/shell crystallites also exhibit a tetrahedral shape, in agreement with a recent model for MSNC growth. Our results indicate that MSNCs can compete with other state-of-the-art semiconductor nanocrystals. Furthermore, these core/shell structures will allow further study of MSNCs and their potential for atomically precise growth.

Keywords

core/shell nanocrystals
CdSe/CdS/ZnS
magic-sized clusters
discrete growth
atomically precise

Supplementary materials

Title
Description
Actions
Title
Supporitng Information
Description
Experimental materials and methods, including details of the synthesis, characterization, and size analysis of the MSNC cores, core/shell MSNCs, and core/shell QDs.
Actions

Comments

Comments are not moderated before they are posted, but they can be removed by the site moderators if they are found to be in contravention of our Commenting Policy [opens in a new tab] - please read this policy before you post. Comments should be used for scholarly discussion of the content in question. You can find more information about how to use the commenting feature here [opens in a new tab] .
This site is protected by reCAPTCHA and the Google Privacy Policy [opens in a new tab] and Terms of Service [opens in a new tab] apply.