Education

B.S., 2000, Massachusetts Institute of Technology
Ph.D., 2006, Harvard University

Honors and Awards

University of South Carolina Two Thumbs Up Award, 2018; ACS-CEI Award for Incorporating Sustainability into Chemistry Education, Committee on Environmental Improvement, American Chemical Society, 2014; Sustainable Carolina Curriculum Award, USC, 2013 and 2015.

Research Interests

Crystalline materials with nanometer-scale physical dimensions often display different properties than bulk crystals of the same compounds, because they are smaller than characteristic length scales for light absorption and scattering, excited electronic states, and charge transport (conductivity).  This is most readily seen in the size-dependent absorption and emission spectra of fluorescent semiconductor nanocrystal “quantum dots.”

Quantum dots are now ubiquitous in fluorescent backlights for flat panel TVs, computer monitors, and mobile devices because their narrow emission spectra allow the rendering of highly saturated colors.  However, only a limited understanding exists of many details of the chemical and physical properties of colloidal quantum dots.  

Our group develops surface-sensitive metrics, purification strategies, and synthetic steps for QDs and other colloidal nanocrystals that permit increasingly precise and sophisticated control of the resulting physical and chemical properties.  Such control is necessary for improving the performance of QD solar cells and other nanocrystal-based devices, and for advancing the biomedical applications of nanocrystal-based imaging and therapeutic agents.  We are also interested in the transport of matter, charge, and energy within nanoscale systems and across interfaces. We use microfabrication, optoelectronic measurements, and functional imaging techniques to characterize these transport processes.

Graduate and undergraduate students with a variety of academic interests including physical, inorganic, and organic chemistry; physics; biological sciences; and electrical engineering will be able to make strong contributions to the group’s research.  Group members employ techniques including air-free synthetic chemistry, NMR spectroscopy, calorimetry, chemical vapor deposition, scanning and transmission electron microscopy, microfabrication, and photoluminescence imaging and spectroscopy.  Instrument control, data analysis, and technical image analysis is done with computational tools such as Matlab and Labview.  Please consult our group’s research website for information on current projects and opportunities to get involved.

Selected Publications

Bobby G. Barker Jr., Venkata Surya N. Chava, Kevin M. Daniels, M. V. S. Chandrashekhar, and Andrew B. Greytak. "Sub-bandgap response of graphene/SiC Schottky emitter bipolar phototransistor examined by scanning photocurrent microscopy." 2D Materials 2018, 5, 011003. DOI: 10.1088/2053-1583/aa90b1.

Yi Shen, Adam Roberge, Rui Tan, Megan Y. Gee, Dylan C. Gary, Yucheng Huang, Douglas A. Blom, Brian C. Benicewicz, Brandi M. "Cossairt and Andrew B. Greytak. Gel permeation chromatography as a multifunctional processor for nanocrystal purification and on-column ligand exchange chemistry." Chemical Science 2016, 7, 5671. DOI: 10.1039/C6SC01301E.

Xia Zhao, Yi Shen, Enoch A. Adogla, Anand Viswanath, Rui Tan, Brian C. Benicewicz, Andrew B. Greytak, Yuan Lin, and Qian Wang.  "Surface labeling of enveloped virus with polymeric imidazole ligand-capped quantum dots via metabolic incorporation of phospholipid in host cells." J. Mater. Chem. B. 2016, 4, 2421.
DOI: 10.1039/C6TB00263C.

Yi Shen, Rui Tan, Megan Y. Gee, and Andrew B. Greytak.  "Quantum Yield Regeneration: Influence of Neutral Ligand Binding on Photophysical Properties in Colloidal Core/Shell Quantum Dots." ACS Nano 2015, 9, 3345. DOI: 10.1021/acsnano.5b00671.

Rui Tan, Douglas A. Blom, Shuguo Ma, and Andrew B. Greytak. "Probing surface saturation conditions in alternating layer growth of CdSe/CdS core/shell quantum dots." Chemistry of Materials 2013, 25, 3724. DOI: 10.1021/cm402148s.