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Magnetic Field Sensor Based on a OLED/Organic Photodetector Stack



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 the large magneto-electroluminescence (MEL) of a thermally activated delayed fluorescence (TADF)-emitter based OLED. The OLED emitter material is a co-deposited blend of Tri[3-(3-pyridyl)mesityl]borane (3TPYMB) and 4,4′,4′′-Tris[phenyl(m-tolyl)amino]triphenylamine (m-MTDATA) which in reference devices have shown an MEL of about 60% for magnetic fields on the order of 10 mT. The OPD is based on a solution processed P3HT:PCBM absorber layer. OLED and OPD are separated from each other by a thin, solution processable dielectric spacer layer. In the monolithic architecture a MEL of about 10% is measured by the OPD. Maximum sensitivity of about 0.15 nA/mT (150 µV/mT or 15 mV/kG when using a current pre-amp with gain of 106 V/A) is achieved near a magnetic field of 3 mT to 4 mT. However, the detectivity at this time is limited to 10-3 T·Hz-1/2. We believe this can be improved upon on, as the sensitivity of TADF-OLEDs measured by an external Si-detector is about an order of magnitude higher with approximately 2 nA/mT and reaches detectivities better than 10-5 T·Hz -1/2.
ACS Applied Electronic Materials


Magnetometer, Organic Light Emitting Diodes, Thermally Assisted Delayed Fluorescence, Magnetic field response, Organic Photodetector, P3HT/PCBM


Engmann, S. , Bittle, E. and Gundlach, D. (2023), Magnetic Field Sensor Based on a OLED/Organic Photodetector Stack, ACS Applied Electronic Materials, [online],, (Accessed May 26, 2024)


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Created August 1, 2023, Updated September 11, 2023