Layered metal dichalcogenides LMDs are exciting 2D semiconductors for energy harvesting and photon detector. Tin disulfide SnS2 was introduced and characterized as an emerging LMD for potential optoelectronic and photon detector applications. With the presence of strong light matter interactions, LMDs were found to exhibit weaker photon absorption due to their ultrathin thickness. Combination of LMDs with other semiconductor nanomaterials will increase the photon absorption. Among such nanomaterials colloidal quantum dots have strong light absorption and size tunable emission.
The combination of zero dimensional (0D) quantum dots and two dimensional (2D) Tin Disulfide is said to have the advantage of increasing photon absorption, a property useful for the development of LMD-base optoelectronic devices.
Dr. Mircea Cotlet and colleagues from Brookhaven National Laboratory in collaboration with Dr. Peter Sutter’s group now at the University of Nebraska-Lincoln combined colloidal CdSe/ZnS Quantum dots with single and few layers of Tin Disulfide to generate hybrids with improved light harvesting properties through non radiative energy transfer. The research work is published in the journal ACS Nano.
To achieve conditions for non-radiative energy transfer they chose quantum dots sized so that their emission overlaps with the optical absorption of layered SnS2, a requirement in order to enable energy transfer between the two semiconducting nanomaterials. To avoind the possibility of charge transfer they chose to utilize quantum dots in the form of core/shell CdSe/ZnS with the shell preventing that particular process. The research team used single nanocrystal photoluminescence spectroscopy to investigate energy transfer and found an increase in the transfer rate with the increase in the number of SnS2 layers. In the same study the team demonstrated the usefulness of single nanocrystals photoluminescence blinking studies to discriminate between energy and change transfer in 0D-2D quantum dot-LMD hybrids, two light stimulated processes which both quench the emission of quantum dots. Photoluminescence blinking or the switching on and off of the emitted light of a quantum dot following continuous light exposure is a property observable only at the single nanocrystal level. By comparing the blinking behavior of quantum dots deposited on a SiO2/Si substrate and on single and few layer SnS2 the researchers pointed out that lack of change in blinking dynamics for quantum dots on either of the above mentioned substrates, opposite to previous reports from the same group and from others suggesting charge transfer from quantum dots to acceptor molecules can modify the blinking dynamics.
Huidong Zang1, Prahlad K. Routh1,2, Yuan Huang1,2, Jia-Shiang Chen1,2, Eli Sutter3, Peter Sutter4 and Mircea Cotlet1, Nonradiative Energy Transfer From Individual CdSe/ZnS Quantum Dots to Single-Layer a d Few-Layer Tin Disulfide, ACS NANO 2016, 10, 4790 −4796.Show Affiliations
- Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, New York 11973, United States
- Materials Science Department, Stony Brook University, Stony Brook, New York 11794, United States
- Department of Mechanical and Materials Engineering, University of Nebraska—Lincoln, Lincoln, Nebraska 68588, United States
- Department of Electrical and Computer Engineering, University of Nebraska—Lincoln, Lincoln, Nebraska 68588, United States
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