Stable Glasses of Organic Semiconductor Resist Crystallization
- 24 December 2020
- journal article
- research article
- Published by American Chemical Society (ACS) in The Journal of Physical Chemistry B
- Vol. 125 (1), 461-466
- https://doi.org/10.1021/acs.jpcb.0c09925
Abstract
The instability of glassy solids poses a key limitation to their use in several technological applications. Well-packed organic glasses, prepared by physical vapor deposition (PVD), have drawn attention recently because they can exhibit significantly higher thermal and chemical stability than glasses prepared from more traditional routes. We show here that PVD glasses can also show enhanced resistance to crystallization. By controlling the deposition temperature, resistance toward crystallization can be enhanced by at least a factor of ten in PVD glasses of the model organic semiconductor Alq3 (tris(8-hydroxyquinolinato) aluminum). PVD glasses of Alq3 first transform into a supercooled liquid before crystallizing. By controlling the deposition temperature, we increase the glass → liquid transformation time thereby also increasing the overall time for crystallization. We thus demonstrate a new strategy to stabilize glasses of organic semiconductors against crystallization, which is a common failure mechanism in organic light emitting diode devices.Keywords
Funding Information
- Basic Energy Sciences (DE-SC0002161)
This publication has 49 references indexed in Scilit:
- Quantitative Determination of Organic Semiconductor Microstructure from the Molecular to Device ScaleChemical Reviews, 2012
- Structural Variations of an Organic Glassformer Vapor-Deposited onto a Temperature Gradient StageThe Journal of Physical Chemistry Letters, 2011
- Molecular orientation in small-molecule organic light-emitting diodesJournal of Materials Chemistry, 2011
- Anisotropic Structure and Transformation Kinetics of Vapor-Deposited Indomethacin GlassesThe Journal of Physical Chemistry B, 2010
- Stability of thin film glasses of toluene and ethylbenzene formed by vapor deposition: an in situ nanocalorimetric studyPhysical Chemistry Chemical Physics, 2010
- Quantification of Thin Film Crystallographic Orientation Using X-ray Diffraction with an Area DetectorLangmuir, 2010
- Highly Stable Indomethacin Glasses Resist Uptake of Water VaporThe Journal of Physical Chemistry B, 2009
- The case for bulk metallic glassMaterials Today, 2004
- Degradation of Organic Electroluminescent Devices. Evidence for the Occurrence of Spherulitic Crystallization in the Hole Transport LayerLangmuir, 1998
- Formation of Glasses from Liquids and BiopolymersScience, 1995