Issue 2, 2019

Carbon dots produced via space-confined vacuum heating: maintaining efficient luminescence in both dispersed and aggregated states

Abstract

Aggregation-induced quenching (AIQ) of emission is an obstacle for the development of carbon dots (CDots) for solid-state luminescent devices. In this work, we introduce a method to avoid AIQ and to produce highly luminescent CDots through a space-confined vacuum heating synthesis. In the presence of CaCl2, a mixture of citric acid and urea forms an inflated foam under vacuum heating at 120 °C. Upon gradually increasing the heating temperature to 250 °C, blue emissive molecular species are first formed, and are then transformed into uniform-sized green emissive CDots through dehydration and carbonization processes taking place in the confined ultrathin spaces of the foam walls. The green luminescence of these CDots originates from conjugated sp2 domains, and these CDots exhibit a high photoluminescence quantum yield (PLQY) of 72% in ethanol solution. Remarkably, due to the existence of only one type of recombination center in these nanoparticles, AIQ does not take place in CDot-based close-packed films, which show strong emission with a PLQY of 65%. Utilizing the differences in the emission properties of vacuum heating produced CDots, CDots synthesized through microwave-assisted heating, and commercial green fluorescent organic ink (namely, excitation-dependent vs. excitation-independent emission, and different stability against photobleaching), multilevel data encryption has been demonstrated.

Graphical abstract: Carbon dots produced via space-confined vacuum heating: maintaining efficient luminescence in both dispersed and aggregated states

Supplementary files

Article information

Article type
Communication
Submitted
17 aug 2018
Accepted
01 nov 2018
First published
02 nov 2018

Nanoscale Horiz., 2019,4, 388-395

Carbon dots produced via space-confined vacuum heating: maintaining efficient luminescence in both dispersed and aggregated states

D. Zhou, P. Jing, Y. Wang, Y. Zhai, D. Li, Y. Xiong, A. V. Baranov, S. Qu and A. L. Rogach, Nanoscale Horiz., 2019, 4, 388 DOI: 10.1039/C8NH00247A

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements