Direct Cd-to-Pb Exchange of CdSe Nanorods into PbSe/CdSe Axial Heterojunction Nanorods

Dongkyu Lee, Whi Dong Kim, Seokwon Lee, Wan Ki Bae, Sangheon Lee, Doh C. Lee

Research output: Contribution to journalArticlepeer-review

35 Scopus citations

Abstract

We report synthesis of PbSe nanorods (NRs) and PbSe/CdSe axial heterojunction NRs via direct Cd-to-Pb cation exchange in CdSe NRs. Use of suited ligand-cation combinations enables the cation exchange while keeping the nanomaterial morphology intact. For example, solvation of Cd2+ using oleylamine (OLA) allows for the cation exchange process, which would not be possible by using oleic acid instead of OLA. A mild cation exchange process, such as mixing Pb-oleate and OLA with CdSe NRs at 130 or 150 °C, results in anisotropic replacement of CdSe into PbSe along the <0001a> direction of wurtzite CdSe, and a partial conversion leads to the formation of heterostructure NRs containing axial CdSe/PbSe heterojunctions. While the cation exchange proceeds at both tips of CdSe NRs, exchange appears to be faster on (0001¯) planes. Binding energy calculation based on density functional theory reveals that OLA binds strongly to the (0001¯) facet of CdSe NRs, leading to asymmetric cation exchange. This protocol to convert CdSe nanocrystals directly into PbSe broadens the design range of CdSe/PbSe heterojunction nanomaterials potentially with various morphologies because template CdSe nanocrystals can be prepared in different shapes via colloidal synthesis.

Original languageEnglish
Pages (from-to)5295-5304
Number of pages10
JournalChemistry of Materials
Volume27
Issue number15
DOIs
StatePublished - 11 Aug 2015

Fingerprint

Dive into the research topics of 'Direct Cd-to-Pb Exchange of CdSe Nanorods into PbSe/CdSe Axial Heterojunction Nanorods'. Together they form a unique fingerprint.

Cite this