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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 28: Poster III
CPP 28.25: Poster
Wednesday, March 20, 2024, 11:30–13:30, Poster C
Organic photodiodes for biomedical applications at low light intensities — •Rabiul Islam1, Siddhartha Saggar1, Michael Mertig1,2, and Caroline Murawski1,2 — 1Kurt-Schwabe-Institut für Mess- und Sensortechnik Meinsberg e.V., Kurt-Schwabe-Str. 4, 04736 Waldheim, Germany — 2Technische Universität Dresden, Physikalische Chemie, 01062 Dresden, Germany
We designed organic photodiodes (OPDs) for wearable and implantable optical sensors that are implemented, e.g., in pulse monitoring or fluorescence imaging. Currently, biomedical sensing devices mostly rely on stiff and bulky inorganic semiconductor components and often require additional color filters. In contrast, OPDs enable light detection at higher absorption coefficients and with new form factors being ultra-thin and potentially flexible. Designing organic molecules enables inherent color filtering and device fabrication requires comparably low thermal budgets. All these characteristics make OPDs an ideal candidate for biomedical applications. To detect the often weak intensity signals, OPDs need to possess low dark currents and low noise. In this study, we fabricated solution-based OPDs using P3HT donor and PC71BM acceptor to demonstrate OPDs with reduced dark current, high linear dynamic range, and excellent detection of light intensities as low as 2 pW. Our fabricated OPDs can be used for photoplethysmography to detect the human pulse rate from a fingertip under illumination with white light. Our future research now aims at incorporating the OPDs into functional devices for monitoring neuronal activities by reading fluorescent signals.
Keywords: Organic Photodiodes; Fluorescence Imaging; Optogenetics; Organic Semiconductors; Flexible Electronics