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Full-Text Articles in Chemistry

Determination Of The Polymerisation Rate Of A Low-Toxicity Diacetone Acrylamide-Based Holographic Photopolymer Using Raman Spectroscopy, Dervil Cody, Emilia Mihaylova, Luke O'Neill, Izabela Naydenova Oct 2015

Determination Of The Polymerisation Rate Of A Low-Toxicity Diacetone Acrylamide-Based Holographic Photopolymer Using Raman Spectroscopy, Dervil Cody, Emilia Mihaylova, Luke O'Neill, Izabela Naydenova

Articles

The polymerisation rate of a low-toxicity Diacetone Acrylamide (DA)-based photopolymer has been measured for the first time using Raman spectroscopy. A value for the polymerisation rate of 0.020 s−1 has been obtained for the DA photopolymer by modelling the polymerisation reaction dynamics as a stretched exponential or Kohlrausch decay function. This is significantly lower than the polymerisation rate of 0.100 s−1 measured for the well known Acrylamide (AA)-based photopolymer composition. The effect of the additive glycerol on the polymerisation rate of the DA-based photopolymer has also been investigated. The inclusion of glycerol is observed to increase the rate …


Molecular Helices As Electron Acceptors In High-Performance Bulk Heterojunction Solar Cells, Yu Zhong, M. Tuan Trinh, Rongsheng Chen, Geoffrey E. Purdum, Petr P. Khlyabich, Melda Sezen, Seokjoon Oh, Haiming Zhu, Brandon Fowler, Boyuan Zhang, Wei Wang, Chang-Yong Nam, Matthew Y. Sfeir, Charles T. Black, Michael L. Steigerwald, Yueh-Lin Loo, Fay Ng, X.-Y. Zhu, Colin Nuckolls Sep 2015

Molecular Helices As Electron Acceptors In High-Performance Bulk Heterojunction Solar Cells, Yu Zhong, M. Tuan Trinh, Rongsheng Chen, Geoffrey E. Purdum, Petr P. Khlyabich, Melda Sezen, Seokjoon Oh, Haiming Zhu, Brandon Fowler, Boyuan Zhang, Wei Wang, Chang-Yong Nam, Matthew Y. Sfeir, Charles T. Black, Michael L. Steigerwald, Yueh-Lin Loo, Fay Ng, X.-Y. Zhu, Colin Nuckolls

Publications and Research

Despite numerous organic semiconducting materials synthesized for organic photovoltaics in the past decade, fullerenes are widely used as electron acceptors in highly efficient bulk-heterojunction solar cells. None of the non-fullerene bulk heterojunction solar cells have achieved efficiencies as high as fullerene-based solar cells. Design principles for fullerene-free acceptors remain unclear in the field. Here we report examples of helical molecular semiconductors as electron acceptors that are on par with fullerene derivatives in efficient solar cells. We achieved an 8.3% power conversion efficiency in a solar cell, which is a record high for non-fullerene bulk heterojunctions. Femtosecond transient absorption spectroscopy revealed …


Wet Chemical Synthesis And Characterization Of Nanomaterials For Solar Cell Applications, Krystle N. Sy, Ramprasad Gandhiraman, Jessica E. Koehne Aug 2015

Wet Chemical Synthesis And Characterization Of Nanomaterials For Solar Cell Applications, Krystle N. Sy, Ramprasad Gandhiraman, Jessica E. Koehne

STAR Program Research Presentations

During long term space missions, it is necessary to have a reliable source of energy. Solar cells are an easy and reliable way to convert energy from the sun to electrical energy. NASA has used solar cells manufactured on Earth as an energy source for many of its missions. In order to develop technologies that will enable high efficiency solar cells, we are synthesizing nanostructured materials. A range of nanostructured materials, such as titanium dioxide nanowires, nickel nanoparticles, copper nanoparticles, and silver nanoparticles/nanowires, are synthesized. In this work, we are reporting on the synthesis of these nanomaterials and the electron …


Temperature Dependent C-Axis Hole Mobilities In Rubrene Single Crystals Determined By Time-Of-Flight, Russell L. Lidberg, Tom J. Pundsack, Neale O. Haugen, Lucas R. Johnstone, C. Daniel Frisbie Mar 2015

Temperature Dependent C-Axis Hole Mobilities In Rubrene Single Crystals Determined By Time-Of-Flight, Russell L. Lidberg, Tom J. Pundsack, Neale O. Haugen, Lucas R. Johnstone, C. Daniel Frisbie

Physics and Astronomy Faculty Publications

Hole mobilities (μ) in rubrene single crystals (space group Cmca) along the crystallographic c-axis have been investigated as a function of temperature and applied electric field by the time-of-fight method. Measurements demonstrate an inverse power law dependence on temperature, namely,μ=μ0T−n with n = 1.8, from room temperature down to 180 K. At 296 K, the average value of μ was found to be 0.29 cm2/Vs increasing to an average value of 0.70 cm2/Vs at 180 K. Below 180 K a decrease in mobility is observed with further cooling. Overall, these results confirm the …


Reconfigurable Solid-State Dye-Doped Polymer Ring Resonator Lasers, Hengky Chandrahalim, Xudong Fan Jan 2015

Reconfigurable Solid-State Dye-Doped Polymer Ring Resonator Lasers, Hengky Chandrahalim, Xudong Fan

Faculty Publications

This paper presents wavelength configurable on-chip solid-state ring lasers fabricated by a single-mask standard lithography. The single- and coupled-ring resonator hosts were fabricated on a fused-silica wafer and filled with 3,3′-Diethyloxacarbocyanine iodide (CY3), Rhodamine 6G (R6G) and 3,3′-Diethylthiadicarbocyanine iodide (CY5)-doped polymer as the reconfigurable gain media. The recorded lasing threshold was ~220 nJ/mm2 per pulse for the single-ring resonator laser with R6G, marking the lowest threshold shown by solid-state dye-doped polymer lasers fabricated with a standard lithography process on a chip. A single-mode lasing from a coupled-ring resonator system with the lasing threshold of ~360 nJ/mm2 per pulse …