Light-addressable potentiometric sensor: Difference between revisions
Peter Horn (talk | contribs) →External links: + {{Sensors}} |
Rescuing 1 sources and tagging 0 as dead. #IABot (v1.3.1.1) |
||
Line 17: | Line 17: | ||
==External links== |
==External links== |
||
*[http://www.fh-aachen.de/laps.html fh-aachen.de] |
*[https://web.archive.org/web/20050319223939/http://www.fh-aachen.de/laps.html fh-aachen.de] |
||
*[http://www.fz-juelich.de/ibn/sensorik/bcs-laps-e.html fz-juelich.de] |
*[http://www.fz-juelich.de/ibn/sensorik/bcs-laps-e.html fz-juelich.de] |
||
Revision as of 16:16, 15 May 2017
A light-addressable potentiometric sensor (LAPS) is a sensor that uses light (e.g. LEDs) to select what will be measured. Light can activate carriers in semiconductors.
History
An example is the pH-sensitive LAPS (range pH4 to pH10) that uses LEDs in combination with (semi-conducting) silicon and pH-sensitive Ta2O5 (SiO2; Si3N4) insulator. The LAPS has several advantages over other types of chemical sensors. The sensor surface is completely flat, no structures, wiring or passivation are required. At the same time, the "light-addressability" of the LAPS makes it possible to obtain a spatially resolved map of the distribution of the ion concentration in the specimen. The spatial resolution of the LAPS is an important factor and is determined by the beam size and the lateral diffusion of photocarries in the semiconductor substrate. By illuminating parts of the semiconductor surface, electron-hole pairs are generated and a photocurrent flows. The LAPS is a semiconductor based chemical sensor with an electrolyte-insulator-semiconductor (EIS) structure. Under a fixed bias voltage, the AC (kHz range) photocurrent signal varies depending of the solution. A two-dimensional mapping of the surface from the LAPS is possible by using a scanning laser beam.
Application
![]() | This section is empty. You can help by adding to it. (September 2011) |
In practice
![]() | This section is empty. You can help by adding to it. (September 2011) |
References
External links