Dual emission in Asymmetric “Giant” PbS/CdS/CdS Core/Shell/Shell Quantum Dots
2016 (English)In: Nanoscale, ISSN 2040-3364, E-ISSN 2040-3372, Vol. 8, no 7, 4217-4226 p.Article in journal (Refereed) Published
Semiconducting nanocrystals optically active in the infrared region of the electromagnetic spectrum enable exciting avenues in fundamental research and novel applications compatible with the infrared transparency windows of biosystems such as chemical and biological optical sensing, including nanoscale thermometry. In this context, quantum dots (QDs) with double color emission may represent ultra-accurate and self-calibrating nanosystems. We present the synthesis of giant core/shell/shell asymmetric QDs having a PbS/CdS Zincblende (Zb)/CdS Wurtzite (Wz) structure with double color emission close to the near-infrared (NIR)region. We show that the double emission depends on the excitation condition and analyze the electron-hole distribution responsible of the independent and simultaneous radiative exciton recombination in the PbS core and in the CdS Wz shell, respectively. These results highlight the importance of the driving force leading to preferential crystal growth in asymmetric QDs, and provide a pathway for a rational control of the synthesis of double color emitting giant QDs, leading to the effective exploitation of visible/NIR transparency windows.
Place, publisher, year, edition, pages
2016. Vol. 8, no 7, 4217-4226 p.
Research subject Experimental physics
IdentifiersURN: urn:nbn:se:ltu:diva-11649DOI: 10.1039/C5NR08881JLocal ID: aa9f91d4-d634-41db-a093-cae6dca27de9OAI: oai:DiVA.org:ltu-11649DiVA: diva2:984599
Validerad; 2016; Nivå 2; 20160119 (jacnas)2016-09-292016-09-29Bibliographically approved