Refine
Year of publication
Document Type
- Article (46)
- Conference Proceeding (3)
- Book (1)
- Part of a Book (1)
Keywords
- Light-addressable potentiometric sensor (3)
- LAPS (2)
- Chemical images (1)
- Chemical imaging (1)
- Chemical imaging sensor (1)
- Chemical sensor (1)
- EIS capacitive sensor (1)
- Field-effect device (1)
- MOS (1)
- Negative impedance convertor (1)
- Organic light-emitting diode display (1)
- Potentiometry (1)
- Resonance-mode measurement (1)
- artificial olfactory image (1)
- catalytic metal (1)
- chemical sensor (1)
- electronic nose (1)
- field-effect structure (1)
- gas sensor (1)
- light-addressable potentiometric sensor (1)
Institute
- INB - Institut für Nano- und Biotechnologien (51) (remove)
Light-addressable potentiometric sensors (LAPS) are semiconductor-based potentiometric sensors, with the advantage to detect the concentration of a chemical species in a liquid solution above the sensor surface in a spatially resolved manner. The addressing is achieved by a modulated and focused light source illuminating the semiconductor and generating a concentration-depending photocurrent. This work introduces a LAPS set-up that is able to monitor the electrical impedance in addition to the photocurrent. The impedance spectra of a LAPS structure, with and without illumination, as well as the frequency behaviour of the LAPS measurement are investigated. The measurements are supported by electrical equivalent circuits to explain the impedance and the LAPS-frequency behaviour. The work investigates the influence of different parameters on the frequency behaviour of the LAPS. Furthermore, the phase shift of the photocurrent, the influence of the surface potential as well as the changes of the sensor impedance will be discussed.