P8 - Application of PZT Thin-Film Technology for Angular Resolved Flame Detection
- Event
- SENSOR+TEST Conferences 2011
2011-06-07 - 2011-06-09
Nürnberg - Band
- Proceedings IRS² 2011
- Chapter
- IP - Poster Session
- Author(s)
- S. Hoppe, M. Ebermann, N. Neumann - InfraTec GmbH, Dresden (Germany)
- Pages
- 130 - 133
- DOI
- 10.5162/irs11/ip8
- ISBN
- 978-3-9810993-9-3
- Price
- free
Abstract
We demonstrate the application of thin film PZT sensor arrays to build the active elements of a pyroelectric flame detector. The used thin film PZT sensor arrays are produced by PYREOS Ltd, Edinburgh, Scotland.
The PZT thin film is co-sputtered from metal targets in an oxygen atmosphere onto platinized silicon wafers and the PZT film is subsequently patterned in to 3x3 arrays. These films show high pyroelectric coefficients, very low dielectric losses and favourable dielectric constants in combination with a so called self-polarization.
The backside of the wafer is subsequently etched to realize the thin film PZT sensor arrays on a thin supporting silicon oxide/nitride membrane. The thin film PZT technology enables to manufacture chips of very small sizes which allows to fully illuminate an array of 3x3 individually addressable pixels with a 1.5 mm diameter beam. The thickness of the PZT thin film is adjusted to 1.4 microns to maximize the absorption in the wavelength range of 4 to 5 microns by multiple interferences within the PZT film.
The 3x3 sensor arrays are integrated with a 9 channel transimpedance amplifier inside the housing. A high responsivity was realized. Even for each pixel a high specific detectivity can be guaranteed, which is clearly higher compared to other low cost detectors for motion detection or thermopile arrays. A built-in lens forms an intra-focal image of the detected flame. It enables the interpolation between the individual pixel signals. The results ensure a remarkable angular resolution of at least 5 degrees within a 100 degrees field of view.