TY  - JOUR
A1  - Werner, Frederik
A1  - Wagner, Torsten
A1  - Yoshinobu, Tatsuo
A1  - Keusgen, Michael
A1  - Schöning, Michael Josef
T1  - Frequency behaviour of light-addressable potentiometric sensors
T2  - Physica Status Solidi (A)
N2  - 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.
Y1  - 2013
UR  - https://opus.bibliothek.fh-aachen.de/opus4/frontdoor/index/index/docId/5315
SN  - 1521-396X ; 0031-8965
VL  - 210
IS  - 5
SP  - 884
EP  - 891
PB  - Wiley-VCH
CY  - Weinheim
ER  -