A Magnetic field sensor based on OLED / organic photodetector stack.

In this study an all-organic magnetic field sensor based on an organic light emitting diode (OLED) and organic photodetector (OPD) layer stack is presented. This sensor opens possibilities to create printable, flexible magnetic field sensors using commercially viable components, allowing magnetic field sensors to be simply integrated into existing OLED technology. The sensor function is driven by the large magneto-electroluminescence (MEL) of a thermally activated delayed fluorescence (TADF)-emitter based OLED, which in reference devices have shown an MEL of about 60% for magnetic fields on the order of 10 mT.

Pump-probe phase spectroscopy with submilliradian sensitivity and nanosecond time delay using Michelson interferometers.

Using two Michelson interferometers, we describe an experimental scheme for sensitive pump-probe spectral interferometry measurements at long time delays. It has practical advantages over the Sagnac interferometer method typically used when long-time delays are required. First, with the Sagnac interferometer, achieving many nanosecond delays requires expanding the size of the interferometer so that the reference pulse arrives before the probe pulse.

Organic single crystals of charge-transfer complexes: model systems for the study of donor/acceptor interactions.

The charge-transfer (CT) state arising as a hybrid electronic state at the interface between charge donor and charge acceptor molecular units is important to a wide variety of physical processes in organic semiconductor devices. The exact nature of this state depends heavily on the nature and co-facial overlap between the donor and acceptor; however, altering this overlap is usually accompanied by extensive confounding variations in properties due to extrinsic factors, such as microstructure. As a consequence, establishing reliable relationships between donor/acceptor molecular structures, their molecular overlap, degree of charge transfer and physical properties, is challenging.

The role of orientation in the MEL response of OLEDs.

Magneto electroluminescence (MEL) is emerging as a powerful tool to study spin dynamics in organic light emitting diodes (OLEDs). The shape of the MEL response is typically used to draw qualitative inference on the dominant process (singlet fission or triplet fusion) in the device. In this study, we develop a quantitative model for MEL and apply it to devices based on Rubrene, and three solution processable anthradithiophene emitters.