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.

Refractive index gas sensor based on the Tamm state in a one-dimensional photonic crystal: Theoretical optimisation

“…Table 2 compares the values of S, FoM, and DL for the present study with a number of previous experimental and theoretical works 24,[59][60][61][62][63] and highlights how the sensitivity of the proposed sensor is higher. Thus, the proposed device with much better performance than hitherto experimentally demonstrated can be constructed 59,60 . www.nature.com/scientificreports www.nature.com/scientificreports/ conclusion We presented a model for a possible large sensitivity gas sensor based on the Tamm state in a one-dimensional photonic crystal.…”

Mesoporous Thin Films for Acoustic Devices in the Gigahertz Range

“…For the past 20 years, there has been a growing interest in mesoporous materials because of their high surface area of the order of 1000 m 2 /g, the precise control in the pore size and shape, pore arrangement, and tunable surface functionality. , In particular, mesoporous thin films obtained from soft chemistry methods present increasing interest as highly accessible materials with tunable structural, chemical, electronic, and optical properties that open the path to applications in fields such as sensing, environment, energy, and biomedicine. , The optical properties of mesoporous films are easily tunable through physical and chemical methods and are subject to change when exposed to the environment, which opens the field of responsive thin films acting as optical waveguides . Besides, complex architectures such as mesoporous multilayers can be processed as 1D photonic crystals or optical resonators with a selective optical response to vapors with different chemical properties or molecular size. ,, This application exemplifies that molecular, supramolecular, or photonic information can be encoded into the structure of a multilayer at several length scales or indeed combined with the plasmonic response . The extension of all these concepts into the nanoacoustic domain represents promising perspectives of this work.…”

“…46 Besides, complex architectures such as mesoporous multilayers can be processed as 1D photonic crystals or optical resonators with a selective optical response to vapors with different chemical properties or molecular size. 30,47,48 This application exemplifies that molecular, supramolecular, or photonic information can be encoded into the structure of a multilayer at several length scales 6 , or indeed combined with the plasmonic response. 37 The extension of all these concepts into the nanoacoustic domain represents promising perspectives of this work.…”

Electro-responsivity in electrolyte-free and solution processed Bragg stacks

“…20,21 In this context, one dimensional photonic crystals (1D PhCs, or Bragg Stacks) lend themselves to easy integration with stimuli responsive elements, thanks to the easiness of fabrication of such multilayered structures. 15,22,23 Responsivity can be achieved through different functionalities, such as liquid crystals, 24 dielectric nanoparticles, [25][26][27][28] mesoporous structures 6,10,[29][30][31][32] and chemical groups, 33,34 which are sensitive to chemical and physical external stimuli. 24,[35][36][37][38] However, most of the recent works in the field of electrochromic Bragg mirrors (ECBM) rely on the use of liquid electrolytes that can pose issues in terms of chemical and environmental stability.…”