Off-resonance Photosensitization of a Photorefractive Polymer Composite Using PbS Nanocrystals

Abstract

The photosensitization of photorefractive polymeric composites for operation at 633 nm is accomplished through the inclusion of narrow band gap semiconductor nanocrystals composed of PbS. Unlike previous studies involving photosensitization of photorefractive polymer composites with inorganic nanocrystals, we employ an off-resonance approach where the first excitonic transition associated with the PbS nanocrystals lies at ~1220 nm and not the wavelength of operation. Using this methodology, internal diffraction efficiencies exceeding 82%, two-beam-coupling gain coefficients of 211 cm-1, and response times of 34 ms have been observed, representing some of the best figures of merit reported for this class of materials. These data demonstrate the ability of semiconductor nanocrystals to compete effectively with traditional organic photosensitizers. in addition to superior performance, this approach also offers an inexpensive and easy means by which to photosensitize composite materials. the photoconductive characteristics of the composites used for this study will also be considered.

Department(s)

Chemistry

Keywords and Phrases

Composite materials; Copolymers; Energy gap; Photoreactivity; Photorefractive materials; Photosensitizers; Semiconducting lead compounds, Excitonic transition; Inorganic nanocrystals; Internal diffraction efficiency; Narrow band gap semiconductors; Photorefractive polymer composites; Polymeric composites; Semiconductor nanocrystals; Two-beam coupling, Polymers

International Standard Serial Number (ISSN)

1932-7447

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2015 American Chemical Society (ACS), All rights reserved.

Publication Date

01 Jun 2015

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