Authors:
D. Cardador
;
D. Segura
;
D. Vega
and
A. Rodríguez
Affiliation:
Universitat Politècnica de Catalunya, Spain
Keyword(s):
Photonic Crystals, Pitch, Cavity, Resonance, Transmission, Emission, Q-factor, Gas Sensor.
Related
Ontology
Subjects/Areas/Topics:
Photodetectors, Sensors and Imaging
;
Photonics
;
Photonics, Optics and Laser Technology
Abstract:
Macroporous silicon photonic crystals with a cavity in the middle of their structure have been studied in both, transmission and emission. The initial transmittance of the photonic crystals was increased form 4%-6% up to the value of 25%-30% by performing a rear attach of the samples of approximately 160 µm. The use of wafers with 700 nm of pitch allowed us to fabricate the optical response of the photonic crystals in the ranges of 6.4 µm and 4.6 µm, where different gases have their absorption frequency –such as NO2 or CO. The fabricated samples have been also heated in order to evaluate their viability to be used as selective emitters for gas sensing purposes. Results show a good agreement in the position of the respective peak compared to the transmission spectrum. However, further studies have to be done to place the base of the peak as close as possible to the 0% of emission in order to have a better selective emitter. This work is a starting point for gas detection devices using
macroporous technology in the mid-infrared, which includes ammonia, formaldehyde, carbon monoxide or nitrous oxide, among others.
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