One-Dimensional Carrier Confinement in “Giant” CdS/CdSe Excitonic Nanoshells

Journal Article · Mon Jun 05 00:00:00 EDT 2017 · Journal of the American Chemical Society

DOI:https://doi.org/10.1021/jacs.7b02054· OSTI ID:1361222

Razgoniaeva, Natalia; Moroz, Pavel; Yang, Mingrui; Budkina, Darya S.; Eckard, Holly; Augspurger, Marissa ^[1]; Khon, Dmitriy ^[1]; Tarnovsky, Alexander N.; Zamkov, Mikhail

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1. Department of Chemistry and Biochemistry, St. Mary’s University, San Antonio, Texas 78228, United States

Here, the emerging generation of quantum dot optoelectronic devices offers an appealing prospect of a size-tunable band gap. The confinement-enabled control over electronic properties, however, requires nanoparticles to be sufficiently small, which leads to a large area of interparticle boundaries in a film. Such interfaces lead to a high density of surface traps which ultimately increase the electrical resistance of a solid. To address this issue, we have developed an inverse energy-gradient core/shell architecture supporting the quantum confinement in nanoparticles larger than the exciton Bohr radius. The assembly of such nanostructures exhibits a relatively low surface-to-volume ratio, which was manifested in this work through the enhanced conductance of solution-processed films. The reported core/shell geometry was realized by growing a narrow gap semiconductor layer (CdSe) on the surface of a wide-gap core material (CdS) promoting the localization of excitons in the shell domain, as was confirmed by ultrafast transient absorption and emission lifetime measurements. The band gap emission of fabricated nanoshells, ranging from 15 to 30 nm in diameter, has revealed a characteristic size-dependent behavior tunable via the shell thickness with associated quantum yields in the 4.4–16.0% range.

• Research Organization: Bowling Green State Univ., Bowling Green, OH (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES)
• Grant/Contract Number: SC0016872
• OSTI ID: 1361222
• Alternate ID(s): OSTI ID: 1372222
• Journal Information: Journal of the American Chemical Society, Journal Name: Journal of the American Chemical Society Vol. 139 Journal Issue: 23; ISSN 0002-7863
• Publisher: American Chemical Society
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
77 NANOSCIENCE AND NANOTECHNOLOGY