Detection of Organic Vapors Using Tamm Mode Based Devices Built from Mesoporous Oxide Thin Films

Abstract

In this work, Tamm mode based devices were synthesized using mesoporous thin films as building blocks. Several systems were designed and built, based on silicon and titanium mesoporous oxides obtained through amphiphilic molecules templating approach. The devices were evaluated for organic vapor detection and the obtained results demonstrate that the developed Tamm devices can be used for such purpose. Distributed Bragg reflectors (DBRs) were also synthesized and evaluated as a comparison. In both cases, the detection of organic vapors is possible thanks to capillary condensation inside the well-ordered and accessible porosity that give rise to equivalent results to the ones obtained for the detection of liquids. Both kinds of devices behave in a similar way, but the figure of merit for the Tamm mode based ones is between two and three times larger due to the smaller width of the sensitive band. Moreover, it was demonstrated that the response time of the sensor is less than 80 s in all tested cases. In addition, such parameter clearly depends on both the physicochemical characteristics of the solvents (in particular, boiling temperature and vapor pressure) and the characteristics of the sensor itself. The results presented in this work represent a proof of concept towards the production of robust and reusable detection devices based on the combination of functional mesoporous thin films and the Tamm mode.