Publication
Title
Near-infrared emitting $CuInSe_{2}/CuInS_{2}$ dot core/rod shell heteronanorods by sequential cation exchange
Author
Abstract
 The direct synthesis of heteronanocrystals (HNCs) combining different ternary semiconductors is challenging and has not yet been successful. Here, we report a sequential topotactic cation exchange (CE) pathway that yields CuInSe2/CuInS2 dot core/rod shell nanorods with near-infrared luminescence. In our approach, the Cu+ extraction rate is coupled to the In3+ incorporation rate by the use of a stoichiometric trioctylphosphine-InCl3 complex, which fulfills the roles of both In-source and Cu-extracting agent. In this way, Cu+ ions can be extracted by trioctylphosphine ligands only when the InP bond is broken. This results in readily available In3+ ions at the same surface site from which the Cu+ is extracted, making the process a direct place exchange reaction and shifting the overall energy balance in favor of the CE. Consequently, controlled cation exchange can occur even in large and anisotropic heterostructured nanocrystals with preservation of the size, shape, and heterostructuring of the template NCs into the product NCs. The cation exchange is self-limited, stopping when the ternary core/shell CuInSe2/CuInS2 composition is reached. The method is very versatile, successfully yielding a variety of luminescent CuInX2 (X = S, Se, and Te) quantum dots, nanorods, and HNCs, by using Cd-chalcogenide NCs and HNCs as templates. The approach reported here thus opens up routes toward materials with unprecedented properties, which would otherwise remain inaccessible.
Language
English
Source (journal)
ACS nano
Publication
2015
ISSN
1936-0851
Volume/pages
9:11(2015), p. 11430-11438
ISI
000365464800094
Full text (Publisher's DOI)
Full text (open access)
UAntwerpen
 Faculty/Department Research group [E?say:metaLocaldata.cgzprojectinf] Colouring Atoms in 3 Dimensions (COLOURATOM). Publication type Subject Affiliation Publications with a UAntwerp address