Photostability can be significantly modulated by molecular packing in glasses

Dataset · Sun Apr 10 04:00:00 EDT 2016

DOI:https://doi.org/10.11578/1350776· OSTI ID:1350776

Ediger, Mark ^[1]; de Pablo, Juan ^[2]; Anthony, Lucas ^[2]; Qiu, Yue ^[2]

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1. University of Wisconsin-Madison; University of Wisconsin-Madison
2. University of Chicago

While previous work has demonstrated that molecular packing in organic crystals can strongly influence photochemical stability, efforts to tune photostability in amorphous materials have shown much smaller effects. Here we show that physical vapor deposition can substantially improve the photostability of organic glasses. Disperse Orange 37 (DO37), an azobenzene derivative, is studied as a model system. Photostability is assessed through changes in the density and molecular orientation of glassy thin films during light irradiation. By optimizing the substrate temperature used for deposition, we can increase photostability by a factor of 50 relative to the liquid-cooled glass. Photostability correlates with glass density, with density increases of up to 1.3%. Coarse-grained molecular simulations, which mimic glass preparation and the photoisomerization reaction, also indicate that glasses with higher density have substantially increased photostability. These results provide insights that may assist in the design of organic photovoltaics and light emission devices with longer lifetimes.

• Research Organization: University of Wisconsin-Madison
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
• DOE Contract Number: SC0002161
• OSTI ID: 1350776
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE