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Search Publications by: Sebastian Engmann (Assoc)

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Displaying 1 - 25 of 46

Magnetic Field Sensor Based on a OLED/Organic Photodetector Stack

August 1, 2023
Author(s)
Sebastian Engmann, Emily Bittle, David Gundlach
In this study a novel, all organic magnetic field sensor is presented based on an organic light emitting diode (OLED) and organic photodetector (OPD) with a maximum field sensitivity comparable to commercial Hall-sensors. The sensor function is driven by

Resolving Complex Photoconductivity of Perovskite and Organic Semiconductor Films Using Phase-Sensitive Microwave Interferometry

March 2, 2023
Author(s)
Jasleen Bindra, Pragya Shrestha, Sebastian Engmann, Chad Cruz, Lea Nienhaus, Emily Bittle, Jason Campbell
Complex transient photoconductivity (Δσ) contains rich fingerprints of charge recombination dynamics in photoactive films. However, a direct measure of both real (Δσ′) and imaginary (Δσ″) components has proven difficult using conventional cavity-based time

The role of orientation in the MEL response of OLEDs

July 13, 2021
Author(s)
Sebastian Engmann, Emily Bittle, Lee J. Richter, Rawad Hallani, John Anthony, David J. Gundlach
Magneto electroluminescence (MEL) is emerging as a powerful tool for the study of spin dynamics in emitting devices. The shape of the MEL response is typically used to draw qualitative inference on the dominant process (singlet fission or triplet fusion)

Synergistic effect of carotenoid and silicone-based additives for photooxidatively stable organic solar cells with enhanced elasticity

July 7, 2021
Author(s)
Michela Prete, Elisa Ogliani, Mikkel Bregnhoj, Subham Dastidar, Jonas Lissau, Horst-Gunter Rubahn, Sebastian Engmann, Anne Ladegaard Skov, Michael Brook, Peter Ogilby, Adam Printz, Vida Turkovic, Morten Madsen
Photochemical and mechanical stability are critical factors in the production and application of organic solar cells. While these factors can individually be improved using different additives, there is no example of studies on the combined effects of such

Polarization Dependence of Charge Conduction in Conjugated Polymer Films Investigated with Time- Resolved Terahertz Spectroscopy

March 6, 2020
Author(s)
Timothy J. Magnanelli, Sebastian Engmann, Jared K. Wahlstrand, John C. Stephenson, Lee J. Richter, Edwin J. Heilweil
We interrogate polarization anisotropy associated with charge conduction in films of the block co polymer PCDTPT, consisting of alternating cyclopenta dithiophene (donor) and thiadiazolo pyridine (acceptor) units with respect to sample morphology. Film

Biomimetic Approach to Inhibition of Photooxidation in Organic Solar Cells Using Beta-Carotene as an Additive

October 14, 2019
Author(s)
Sebastian Engmann, Vida Turkovic, Michela Prete, Mikkel Bregnhoj, Liana Inasaridze, Dmytro Volyniuk, Filipp Obrezkov, Juozas V. Grazulevicius, Horst G. Rubahn, Pavel Troshin, Peter R. Ogilby, M. Madsen
Recent improvements in the power conversion efficiencies of organic photovoltaic (OPV) cells have highlighted the fact that OPV device lifetimes are now the main bottleneck for further advances of this technology. As such, understanding and controlling

Morphology of a thermally stable small molecule OPV blend comprising a liquid crystalline donor and fullerene acceptor

June 4, 2019
Author(s)
Alexander J. Bourque, Sebastian Engmann, Allison Fuster, Chad R. Snyder, Lee J. Richter, Paul B. Geraghty, David J. Jones
Recently organic photovoltaic (OPV) devices comprising the small molecule liquid-crystalline donor, benzodithiophene-quaterthiophene-rhodanine (BQR), were demonstrated to achieve high performance when thermally processed, avoiding the need for slow-drying

Higher Order Effects in Organic LEDs with Sub-bandgap Turn-on

January 16, 2019
Author(s)
Sebastian Engmann, Adam J. Barito, Emily Bittle, Chris Giebink, Lee J. Richter, David J. Gundlach
Spin-dependent nonlinear processes in organic materials such as singlet-fission and triplet- triplet annihilation could increase the performance for photovoltaics, detectors, and light emitting diodes. Rubrene/C60 light emitting diodes exhibit a distinct