Thema der Dissertation:
Advancement in the application of the electron paramagnetic resonance on a chip for operando spectroscopy
Advancement in the application of the electron paramagnetic resonance on a chip for operando spectroscopy
Abstract: Electron Paramagnetic Resonance (EPR) spectroscopy is a powerful tool for investigating paramagnetic species by analyzing unpaired electrons. It is widely used across chemistry, biology, and materials science to quantify radical species, detect defects in semiconductors, and study oxygen concentration in biological environments. However, conventional EPR spectrometers rely on bulky electromagnets and microwave resonators, limiting their applicability for in situ and operando studies.
This research presents advancements in EPR spectroscopy through the integration of EPR-on-a-Chip (EPRoC) technology and a compact single-sided permanent magnet. The EPRoC is based on a voltage-controlled oscillator (VCO) that simultaneously generates microwave radiation and detects EPR signals, enabling frequency-swept spectroscopy without the need for large electromagnets. This approach allows for a miniaturized and portable EPR sensor, making EPR accessible for real-world applications.
A key aspect of this work is the combination of the EPRoC with a custom-designed permanent magnet, enabling precise characterization of its magnetic field strength and homogeneity. This setup has been used to develop a calibration method for spin quantification, demonstrating a linear relationship between signal intensity and radical concentration in liquid solutions. This methodology extends the applicability of EPR to environments that were previously inaccessible.
To further explore the capabilities of the EPRoC, operando experiments have been performed using rapid scan EPR to monitor real-time oxygen concentration changes in liquid trityl radical solutions. This technique significantly enhances sensitivity while reducing acquisition time, making it an ideal method for biomedical applications, such as oxygen sensing in biological and medical research.
Additionally, this work explores the potential of electrically detected magnetic resonance on a chip (EDMRoC). A set of hydrogenated amorphous silicon p-i-n solar cells has been fabricated and analyzed, demonstrating that recombination through dangling bond defects is a key process affecting device efficiency. These findings highlight the potential of EDMRoC for semiconductor diagnostics and quantum sensing applications.
Overall, this research represents a significant advancement in EPR technology, paving the way for compact, high-sensitivity spectrometers applicable in materials science, biophysics, and healthcare. The integration of EPRoC with a single-sided permanent magnet and rapid scan capabilities enables portable, real-time, and high-sensitivity EPR spectroscopy for a wide range of scientific and industrial applications.
This research presents advancements in EPR spectroscopy through the integration of EPR-on-a-Chip (EPRoC) technology and a compact single-sided permanent magnet. The EPRoC is based on a voltage-controlled oscillator (VCO) that simultaneously generates microwave radiation and detects EPR signals, enabling frequency-swept spectroscopy without the need for large electromagnets. This approach allows for a miniaturized and portable EPR sensor, making EPR accessible for real-world applications.
A key aspect of this work is the combination of the EPRoC with a custom-designed permanent magnet, enabling precise characterization of its magnetic field strength and homogeneity. This setup has been used to develop a calibration method for spin quantification, demonstrating a linear relationship between signal intensity and radical concentration in liquid solutions. This methodology extends the applicability of EPR to environments that were previously inaccessible.
To further explore the capabilities of the EPRoC, operando experiments have been performed using rapid scan EPR to monitor real-time oxygen concentration changes in liquid trityl radical solutions. This technique significantly enhances sensitivity while reducing acquisition time, making it an ideal method for biomedical applications, such as oxygen sensing in biological and medical research.
Additionally, this work explores the potential of electrically detected magnetic resonance on a chip (EDMRoC). A set of hydrogenated amorphous silicon p-i-n solar cells has been fabricated and analyzed, demonstrating that recombination through dangling bond defects is a key process affecting device efficiency. These findings highlight the potential of EDMRoC for semiconductor diagnostics and quantum sensing applications.
Overall, this research represents a significant advancement in EPR technology, paving the way for compact, high-sensitivity spectrometers applicable in materials science, biophysics, and healthcare. The integration of EPRoC with a single-sided permanent magnet and rapid scan capabilities enables portable, real-time, and high-sensitivity EPR spectroscopy for a wide range of scientific and industrial applications.
Zeit & Ort
05.03.2025 | 16:00
Hörsaal A (1.3.14)
(Fachbereich Physik, Arnimallee 14, 14195 Berlin)