TODAY: Russell Holmes, 12-Dec-24, 12:20pm Central
1 view
Skip to first unread message
Ellad Tadmor
Dec 10, 2024, 9:18:46 AM12/10/24
to aem-solid...@umn.edu
AEM Mechanics Research Seminar
Tuesday 24-Dec-2024, 12:20pm Central
Prof. Russell Holmes
Department of Chemical Engineering and Materials Science, University of Minnesota
Title: The role of molecular orientation and glassy thin film behavior in organic light-emitting devices (OLEDs)
Abstract: Organic semiconductors are conjugated molecular materials with highly tunable electrical and optical functionality. These materials have found wide interest as thin film components in optoelectronic and photovoltaic devices, where attractive physical properties are combined with high-throughput processing on mechanically flexible substrates enabling novel device form factors. To date, the most successful application of organic semiconductor thin films has been in displays based on organic light-emitting devices (OLEDs). An OLED consists of a vertical thin film stack deposited via a high vacuum, physical vapor deposition process. While these layers are typically amorphous and glassy, ongoing work has revealed the complexity and tunability in property and performance that can come with active engineering of molecular orientation.
Central to this talk is how changes in thin film molecular orientation lead to corresponding changes in the associated transition dipole moment (TDM) and permanent dipole moment (PDM) orientations. The TDM orientation plays a role in determining thin film phenomena including birefringence and OLED efficiency, and manipulation of this parameter is already an active part of display design. This talk will focus more heavily on the less widely investigated case of preferential PDM orientation, its impact on charge and molecular excited state (exciton) behavior in OLEDs, and ultimately its impact on efficiency and operational lifetime. Emphasis will also be placed on discussing the means to manipulate PDM orientation via thin film processing conditions and the inclusion of additional dopant molecules, as well as showing how device architecture can be used to mitigate the impact on device performance. The talk will conclude with a discussion of how tuning of molecular orientation in organic thin films represents a largely open axis for engineering the behavior of this important materials class.
For more information, visit the AEM Mechanics Research Seminar website:
Tuesday 24-Dec-2024, 12:20pm Central
In-person: Room 327, Akerman Hall, University of Minnesota
Online: Webinar registration link
Department of Chemical Engineering and Materials Science, University of Minnesota
Title: The role of molecular orientation and glassy thin film behavior in organic light-emitting devices (OLEDs)
Abstract: Organic semiconductors are conjugated molecular materials with highly tunable electrical and optical functionality. These materials have found wide interest as thin film components in optoelectronic and photovoltaic devices, where attractive physical properties are combined with high-throughput processing on mechanically flexible substrates enabling novel device form factors. To date, the most successful application of organic semiconductor thin films has been in displays based on organic light-emitting devices (OLEDs). An OLED consists of a vertical thin film stack deposited via a high vacuum, physical vapor deposition process. While these layers are typically amorphous and glassy, ongoing work has revealed the complexity and tunability in property and performance that can come with active engineering of molecular orientation.
Central to this talk is how changes in thin film molecular orientation lead to corresponding changes in the associated transition dipole moment (TDM) and permanent dipole moment (PDM) orientations. The TDM orientation plays a role in determining thin film phenomena including birefringence and OLED efficiency, and manipulation of this parameter is already an active part of display design. This talk will focus more heavily on the less widely investigated case of preferential PDM orientation, its impact on charge and molecular excited state (exciton) behavior in OLEDs, and ultimately its impact on efficiency and operational lifetime. Emphasis will also be placed on discussing the means to manipulate PDM orientation via thin film processing conditions and the inclusion of additional dopant molecules, as well as showing how device architecture can be used to mitigate the impact on device performance. The talk will conclude with a discussion of how tuning of molecular orientation in organic thin films represents a largely open axis for engineering the behavior of this important materials class.
For more information, visit the AEM Mechanics Research Seminar website:
---
Ellad B. Tadmor, Ph.D.
Russell J. Penrose Professor
Department of Aerospace Engineering and Mechanics
University of Minnesota
https://dept.aem.umn.edu/~tadmor/
Russell J. Penrose Professor
Department of Aerospace Engineering and Mechanics
University of Minnesota
https://dept.aem.umn.edu/~tadmor/
Reply all
Reply to author
Forward
0 new messages