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4. Polarized photoluminescence from poly(p-phenylene-ethynylene) via a block copolymer nanotemplate

Author

Breen, Craig A., Deng, Tao, Breiner, Thomas, Thomas, Edwin L., and Swager, Timothy M.

Subjects
Photoluminescence -- Research, Block copolymers -- Usage, Polymers -- Chemical properties, Polymers -- Structure, Chemistry
Abstract

A new approach to achieve polarized emission from conjugated polymers (CPs), specifically poly(p-phenylene-ethynylene) (PPE), by using a block copolymer host matrix as a nanotemplate for the spatial orientation of CPs is reported, which provides a means of generating large-area films for polarized photoluminescence. The PPEs are indicated to be uniaxially oriented as the host/guest system gives rise to both polarized absorption and photoluminescence parallel to the cylinder axis of the host.

Published
2003

9. Grafted poly(phenylene-ethynylene) : optical and optoelectronic applications

Author

Timothy M. Swager., Massachusetts Institute of Technology. Dept. of Chemistry., Breen, Craig A, Timothy M. Swager., Massachusetts Institute of Technology. Dept. of Chemistry., and Breen, Craig A

Abstract

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemistry, 2005., Vita. Page 198 blank., Includes bibliographical references., Poly(phenylene-ethynylene) (PPE), a fully conjugated polymer system, exhibits high solution state quantum yields, narrow emission profiles, and wide band gaps allowing for blue emission, making them ideal candidates for display applications. Unfortunately, PPEs have received little attention in solid-state optical and optoelectronic applications due to aggregation phenomena, which significantly reduces solid-state emission efficiencies and limits the miscibility of PPEs with other materials systems. Furthermore, the acetylene linkage in PPEs limits the redox properties of these polymers making charge injection, especially holes, difficult without material degradation. However, this dissertation details the development of a grafted PPE system that demonstrates enhanced optical and optoelectronic behavior by circumventing the negative aspects of traditional PPEs outlined above. The basic luminescent properties of conjugated polymer systems are outlined in Chapter 2. Building upon this fundamental understanding, we move to the design and synthesis of a new grafted PPE system described in Chapter 3. The synthetic modification of the PPE is used for domain-specific incorporation into a cylindrical morphology block copolymer host matrix, which is reported in Chapter 4. This work also details the design and fabrication of new PPE based organic light emitting devices (OLEDs). Chapter 5 discusses the development of a new hybrid OLED system whereby energy transfer from a hole-transport host to grafted PPEs results in efficient, blue PPE electroluminescence (EL) that matches the solid-state PL. Moreover, the grafting process is completely modular, allowing for further modification., (cont.) Chapter 6 details the introduction of a charge transport moiety, which is directly grafted to a PPE backbone structure, enabling an entirely polymeric, single layer device, capable of achieving efficient, narrow blue EL. The culmination of these results in Chapter 7 solidifies that PPEs, in combination with a modular grafting technique, can now be accessed as viable light-emitting materials for OLED applications., by Craig A. Breen., Ph.D.

Published
2006

21. P-176: Progress in Developing High Efficiency Quantum Dot Displays

Author

Kazlas, Peter T., primary, Steckel, Jonathan S., additional, Cox, Marshall, additional, Roush, Caroline, additional, Ramprasad, Dorai, additional, Breen, Craig, additional, Misic, Mead, additional, DiFilippo, Vincent, additional, Anc, Maria, additional, Ritter, John, additional, and Coe-Sullivan, Seth, additional

Published
2007
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26. 12.1: Invited Paper: Quantum Dots: The Ultimate Down-Conversion Material for LCD Displays.

Author

Steckel, Jonathan S., Ho, John, Hamilton, Charles, Breen, Craig, Liu, Wenhao, Allen, Peter, Xi, Jingqun, and Coe‐Sullivan, Seth

Subjects
QUANTUM dots, REPRODUCIBLE research, LIQUID crystal displays, NTSC (Television format), LIQUID crystal display television sets
Abstract

Assuming large color gamut and therefore better color reproducibility will be a highly desired feature of all displays as we look to the near future, we make the case in this paper that Quantum Dots (QDs) are currently the down-conversion technology of choice that will allow liquid crystal display (LCD) makers to cost-effectively reach and exceed 100% of the NTSC (National Television Standard Committee) standard while achieving maximum system efficiency. We will discuss in detail the numerous fundamental advantages of QDs over phosphors, along with their scientific origins, and make the case that QDs are the ultimate light generating material for next-generation displays. [ABSTRACT FROM AUTHOR]

Published
2014
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27. Facile in Situ Silver Nanoparticle Formation in Insulating Porous Polymer Matrices

Author

Rifai, Sandra, A. Breen, Craig, J. Solis, Daniel, and M. Swager, Timothy

Abstract

The in situ formation of well-dispersed silver nanoparticles in an insulating polymer matrix is reported. Poly(aryl ether)s (PAEs) incorporating an oxadiazole moiety were synthesized, and they demonstrated selective interaction with silver ions. Polymer−ion thin films were easily spin cast and exposed to hydrazine vapors in order to induce metal nucleation. Introducing a triptycene monomer into the polymer backbone resulted in a highly porous matrix and prevented nanoparticle aggregation. This provides a generalized approach to the facile preparation of well-dispersed metal nanoparticle embedded thin films.

Published
2006
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28. 68.1: Invited Paper: Quantum Dot Manufacturing Requirements for the High Volume LCD Market.

Author

Steckel, Jonathan S., Colby, Richard, Liu, Wenhao, Hutchinson, Kirk, Breen, Craig, Ritter, John, and Coe-Sullivan, Seth

Subjects
QUANTUM dots, NANOSTRUCTURED materials, LIQUID crystal displays, COLOR, LIGHTING
Abstract

Quantum dots (QDs) are a luminescent semiconductor nanomaterial technology that delivers exceptional color for liquid crystal display backlighting unit (LCD-BLU) applications. We report on the scale-up of the rapid-injection, batch synthetic method, and compare it to other proposed manufacturing methods. A discussion of how to meet high volume QD production needs follows, consistent with current and future LCD volumes, and taking into account dominant implementation geometries. [ABSTRACT FROM AUTHOR]

Published
2013
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29. Red, green, and blue laser action in solid colloidal quantum dot films.

Author

Dang, Cuong, Kwangdong Roh, Joonhee Lee, Breen, Craig, Steckel, Jonathan S., Coe-Sullivan, Seth, and Nurmikko, Arto

Abstract

We report on wavelength-variable lasing from optical gain media composed of colloidal quantum-dots (CQD) thin films across the visible spectrum. Exploiting single exciton gain enables amplified spontaneous emission (ASE) and vertical cavity lasing at very low optical pump thresholds. The average number of exciton per CQD at the ASE threshold is <N>∼ 0.8, which significantly reduces losses from enhanced nonradiative multiexciton Auger recombination in nanometer sized semiconductor particle, enabling quasi-continuous-wave CQD laser performance in densely packed nanocomposites. [ABSTRACT FROM PUBLISHER]

Published
2012
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