Abstract
Ultrathin colloidal PbS nanosheets are synthesized using organometallic precursors with chloroalkane cosolvents, resulting in tunable thicknesses ranging from 1.2 nm to 4.6 nm. We report the first thickness-dependent photoluminescence spectra from lead-salt nanosheets. The one-dimensional confinement energy of these quasi-two-dimensional nanosheets is found to be proportional to 1/L instead of 1/L2 (L is the thickness of the nanosheet), which is consistent with results calculated using density functional theory as well as tight-binding theory.
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Acknowledgments
The work is partially supported with funding provided by the Office of the Vice President for Research & Economic Development, Bowling Green State University. We thank Charles Codding (machine shop) and Doug Martin (electronic shop) for their technical assistance. High resolution TEM measurements were conducted using a JEOL 3011 high resolution electron microscope (NSF grant #DMR-0315633) at the Electron Microbeam Analysis Laboratory at the University of Michigan. The authors thank Joseph G. Lawrence and Lidia B. Rodriguez for their help on the TEM and FTIR measurements at the University of Toledo. We thank the Texas Advanced Computer Center (TACC) and XSEDE program (project TG-DMR130080) and Ohio Supercomputer Center (project PCS0220) for computational resources.
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Jiang, Z., Khan, S., Premathilake, S. et al. Colloidal PbS Nanosheets with Tunable Energy Gaps. MRS Online Proceedings Library 1726, 13–18 (2014). https://doi.org/10.1557/opl.2015.463
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DOI: https://doi.org/10.1557/opl.2015.463