Issue 30, 2006

Solid state NMR studies of photoluminescent cadmium chalcogenide nanoparticles

Abstract

Solid state 113Cd, 77Se, 13C and 31P NMR have been used to study a number of Cd chalcogenide nanoparticles synthesized in tri-n-octyl-phosphine (TOP) with different compositions and architectures. The pure CdSe and CdTe nanoparticles show a dramatic, size-sensitive broadening of the 113Cd NMR line, which can be explained in terms of a chemical shift distribution arising from multiple Cd environments. From 13C NMR, it has been discovered that TOP, or its derivatives such as TOPO (trioctylphosphine oxide), is rapidly moving about the surface of the nanoparticles, indicating that it is relatively weakly bound as compared to other materials used as surface ligands, such as hexadecylamine. 31P NMR of the nanoparticles shows at least five species arising from coordination of the ligands to different surface sites. 113Cd NMR of CdSeTe alloy and layered nanoparticles has provided crucial information which, in conjunction with results from other techniques (especially optical characterization), has made it possible to develop a detailed picture of the composition and structure of these materials: (i) a true CdSeTe homogeneous alloy nanoparticle, (ii) a nanoparticle segregated into an alloy core region rich in Te, with a CdSeTe (close to 1 : 1 Se : Te) alloy shell and (iii) a CdSe/CdTe/CdSe layered nanoparticle in which the CdTe layer contains a small amount of Se and which forms a Quantum Dot Quantum Well (QDQW) system. The results demonstrate that solid state NMR is a vital tool in the arsenal of characterisation techniques available for nanomaterials.

Graphical abstract: Solid state NMR studies of photoluminescent cadmium chalcogenide nanoparticles

Article information

Article type
Paper
Submitted
08 May 2006
Accepted
14 Jun 2006
First published
03 Jul 2006

Phys. Chem. Chem. Phys., 2006,8, 3510-3519

Solid state NMR studies of photoluminescent cadmium chalcogenide nanoparticles

C. I. Ratcliffe, K. Yu, J. A. Ripmeester, Md. Badruz Zaman, C. Badarau and S. Singh, Phys. Chem. Chem. Phys., 2006, 8, 3510 DOI: 10.1039/B606507B

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