Self-heating effects in large arrangements of randomly oriented carbon nanofibers: Application to gas sensors

Monereo, O.; Prades, Joan Daniel; Cirera, A.

doi:10.1016/j.snb.2015.01.095

Cited by 41 publications

(54 citation statements)

References 68 publications

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“…In both experiments, equivalent responses were obtained but their dynamics were clearly different. This fact may originate from differences in the local temperature achieved by each nanowire in self-heating mode, which leads to an overall response signal that averages the dynamics of nanowires operating at different temperatures [42].…”

Section: Application To Gas Sensingmentioning

confidence: 99%

Facile integration of ordered nanowires in functional devices

Guilera

Fàbrega

Casals³

et al. 2015

Sensors and Actuators B: Chemical

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Section: Application To Gas Sensingmentioning

confidence: 99%

Facile integration of ordered nanowires in functional devices

Guilera

Fàbrega

Casals³

et al. 2015

Sensors and Actuators B: Chemical

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“…These arguments justified the need of individual nanostructures, and suggested that such effects were just unfeasible in large arrangements of nanowires 27 . However, as previously stated, recent experiments show that this is not the case: efficient self-heating can also be achieved in random arrangements of multiple 1D nanostructures 23,25 . This work aims to shed some light on the issue, identifying a broad, general cause for efficient self-heating in nanostructured systems.…”

Section: Introductionmentioning

confidence: 86%

“…That is the reason why this promising approach has just remained as an object of research, with limited applicability 22 .…”

Section: Introductionmentioning

confidence: 99%

“…nanowires 23 , nanotubes 24 and nanofibers 25 ) showed that the requirement of individual nanowires was a misconception. In fact, randomly deposited nanofibers exhibit self-heating effects with performance figures for power dissipation and thermalization time comparable to those of individual nanowires 22 . For example, operation temperatures of 150 °C with less than 50 W and thermalization times of less than 50 ms were reported 26 in carbon nanofibers (CNFs) deposited on top of macroscopic interdigitated electrodes (IDE) by techniques as simple as drop casting.…”

Section: Introductionmentioning

confidence: 99%

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Localized self-heating in large arrays of 1D nanostructures

et al. 2016

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One dimensional (1D) nanostructures offer a promising path towards a highly efficient heating and temperature control in integrated microsystems. The so called self-heating effect can be used to modulate the response of solid state gas sensor devices. Efficient self-heating was found to occur at random networks of nanostructured systems with similar power requirements than in highly ordered systems (e.g. individual nanowires, where its thermal efficiency attributed to the small dimensions of the objects). In this work, infrared thermography and Raman spectroscopy were used to map the temperature profiles of films based on random arrangements of carbon nanofibers during self-heating occurrence. Both techniques demonstrate consistently that heating concentrates in small regions, the here-called "hot-spots". Correlating dynamic temperature mapping with electrical measurements, we also observed that these minute hot-spots rule the resistance values observed macroscopically. A physical model of a random network of 1D resistors helped us to explain this observation. The model shows that, for a given random arrangement of 1D nanowires, current spreading though the network ends up defining a set of spots that dominate both the electrical resistance and the power dissipation. Such highly localized heating explains the high power savings observed in larger nanostructured systems. This understanding opens a path to design highly efficient self-heating systems, based on random or pseudo-random distributions of 1D nanostructures.

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“…Second, to provide the activation energies necessary for the interaction of gas molecules with the oxide surface, since the gas adsorption or desorption on MOx is an endothermic processes 1 . Typically, thermal heating (in the range of 200-500 ˚C) or non-equilibrium processes (light illumination, UV or visible) are applied to provide the needed energies for surface activation 2,3 . Recently, we reported a promising concept to realize self-powered gas sensors that are capable of detecting gases at zero power.…”

mentioning

confidence: 99%

Integrated Strategy toward Self-Powering and Selectivity Tuning of Semiconductor Gas Sensors

et al. 2016

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Inorganic conductometric gas sensors struggle to overcome limitations in high power consumption and poor selectivity. Herein, recent advances in developing self-powered gas sensors with tunable selectivity are introduced. Alternative general approaches for powering gas sensors were realized via proper integration of complementary functionalities (namely; powering and sensing) in a singular heterostructure. These solar light driven gas sensors operating at room temperature without applying any additional external powering sources are comparatively discussed. The TYPE-1 gas sensor based on integration of pure inorganic interfaces (e.g. CdS/n-ZnO/p-Si) is capable of delivering a self-sustained sensing response, while it shows a non-selective interaction towards oxidizing and reducing gases. The structural and the optical merits of TYPE-1 sensor are investigated giving more insights into the role of light activation on the modulation of the selfpowered sensing response. In the TYPE-2 sensor, the selectivity of inorganic materials is tailored through surface functionalization with self-assembled organic monolayers (SAMs). Such hybrid interfaces (e.g. SAMs/ZnO/p-Si) have specific surface interactions with target gases compared to the non-specific oxidation-reduction interactions governing the sensing mechanism of simple inorganic sensors. The theoretical modeling using density functional theory (DFT) has been used to simulate the sensing behavior of inorganic/organic/gas interfaces, revealing that the alignment of organic/gas frontier molecular orbitals with respect to the inorganic Fermi level is the key factor for tuning selectivity. These platforms open new avenues for developing advanced energy-neutral gas sensing devices and concepts.

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Self-heating effects in large arrangements of randomly oriented carbon nanofibers: Application to gas sensors

Cited by 41 publications

References 68 publications

Facile integration of ordered nanowires in functional devices

Facile integration of ordered nanowires in functional devices

Localized self-heating in large arrays of 1D nanostructures

Integrated Strategy toward Self-Powering and Selectivity Tuning of Semiconductor Gas Sensors

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