“Inspired by the promise of enhanced spectral response, photorefractive polymeric composites photosensitized with semiconductor nanocrystals have emerged as an important class of materials. Here, we report on the photosensitization of photorefractive polymeric composites at visible wavelengths through the inclusion of narrow band-gap semiconductor nanocrystals composed of PbS. Through this approach, internal diffraction efficiencies in excess of 82%, two-beam-coupling gain coefficients in excess of 211 cm-1, and response times 34 ms have been observed, representing some of the best figures-of-merit reported on this class of materials. In addition to providing efficient photosensitization, however, extensive studies of these hybrid composites have indicated that the inclusion of nanocrystals also provides an enhancement in the charge-carrier mobility and subsequent reduction in the photorefractive response time. Through this approach with PbS as charge-carrier, unprecedented response times of 399 µs were observed, opening the door for video and other high-speed applications. It is further demonstrated that this improvement in response time occurs with little sacrifice in photorefractive efficiency and with internal diffraction efficiencies of 72% and two-beam- coupling gain coefficients of 500 cm-1 being measured. A thorough analysis of the experimental data is presented, supporting the hypothesized mechanism of the enhanced charge mobility without the accompaniment of superfluous traps. Finally, water soluble InP/ZnS and CdSe/ZnS quantum dots interacted with CPP and Herceptin to apply them as a bio-maker. Both of quantum dots showed the excellent potential for use in biomedical imaging and drug delivery applications. It is anticipated that these approaches can play a significant role in the eventual commercialization of these classes of materials."--Abstract, page iv.
Winiarz, Jeffrey G.
Ph. D. in Chemistry
Missouri University of Science and Technology. Materials Research Center
Missouri University of Science and Technology. Department of Chemistry
Missouri University of Science and Technology
Journal article titles appearing in thesis/dissertation
- Off-resonance photosensitization of a photorefractive polymer composite using PbS nanocrystals
- Sub-millisecond response time in a photorefractive composite operating under CW conditions
- Formation of water soluble wavelength tunable InGaP and InP quantum dots
- Synthesis, characterization and applications of carboxylated and polyethylene-glycolated bifunctionalized InP/ZnS quantum dots in cellular internalization mediated by cell-penetrating peptides
- Specific intracellular uptake of herceptin-conjugated CdSe/ZnS quantum dots into breast cancer cells
xiii, 184 pages
© 2014 Jong-Sik Moon, All rights reserved.
Dissertation - Open Access
Electronic OCLC #
Link to Catalog Record
Moon, Jong-Sik, "Semiconductor nanocrystals for novel optical applications" (2014). Doctoral Dissertations. 2370.