Chemical substitution of Cd ions by Hg in CdSe nanorods and nanodots: Spectroscopic and structural examination

• Published in: Materials science & engineering. B, Solid-state materials for advanced technology Solid-state materials for advanced technology, 2012-06, Vol.177 (10), p.744-749
• Main Authors: Prudnikau, Anatol, Artemyev, Mikhail, Molinari, Michael, Troyon, Michel, Sukhanova, Alyona, Nabiev, Igor, Baranov, Alexandr V., Cherevkov, Sergey A., Fedorov, Anatoly V.
• Format: Article
• Language: English
• Subjects: Blends; Cadmium; Cadmium selenides; CdSe; Chemical substitution; Engineering Sciences; HgSe; Intermetallics; Mercury; Micro and nanotechnologies; Microelectronics; Nanorods; Nanostructure; Quantum dots; Spectroscopy; Zinc
• ISSN: 0921-5107; 1873-4944
• DOI: 10.1016/j.mseb.2011.12.038

► We studied cadmium-by-mercury chemical substitution in CdSe nanocrystals. ► Zinc blende CdSe quantum dots can be easily converted to isostructural CdxHg1−xSe. ► Wurtzite CdSe QDs require longer time to convert to a zinc blende CdxHg1−xSe. ► Wurtzite CdSe nanorods transform to nanoheterogeneous luminescent CdxHg1−xSe rods. The chemical substitution of cadmium by mercury in colloidal CdSe quantum dots (QDs) and nanorods has been examined by absorption, photoluminescence and Raman spectroscopy. The crystalline structure of original CdSe QDs used for Cd/Hg substitution (zinc blende versus wurtzite) shows a strong impact on the optical and structural properties of resultant CdxHg1−xSe nanocrystals. Substitution of Cd by Hg in isostructural zinc blende CdSe QDs converts them to ternary CdxHg1−xSe zinc blende nanocrystals with significant NIR emission. Whereas, the wurtzite CdSe QDs transformed first to ternary nanocrystals with almost no emission followed by slow structural reorganization to a NIR-emitting zinc blende CdxHg1−xSe QDs. CdSe nanorods with intrinsic wurtzite structure show unexpectedly intense NIR emission even at early Cd/Hg substitution stage with PL active zinc blende CdxHg1−xSe regions.