Vapor Detection Performance of Vertically Aligned, Ordered Arrays of Silicon Nanowires with a Porous Electrode

Field, Christopher R.; In, Hyun Jin; Begue, Nathan J.; Pehrsson, Pehr E.

doi:10.1021/ac200779d

Cited by 28 publications

(21 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To evaluate the chem/biosensing capabilities of our PTE SiNW array sensors, the completed devices were exposed to varying levels of NO 2 or NH 3 in a custom-built testing chamber. The specifics of the testing chamber and conditions have been described elsewhere [22]. Without further treatment or modification of silicon, surface adsorption of electronwithdrawing (donating) species like NO 2 (NH 3 ) decreases (increases) the overall resistance of our p-type Si devices.…”

Section: Resultsmentioning

confidence: 99%

Periodically porous top electrodes on vertical nanowire arrays for highly sensitive gas detection

Field

Pehrsson

2011

Nanotechnology

Self Cite

View full text Add to dashboard Cite

Nanowires of various materials and configurations have been shown to be highly effective in the detection of chemical and biological species. In this paper, we report a novel, nanosphere-enabled approach to fabricating highly sensitive gas sensors based on ordered arrays of vertically aligned silicon nanowires topped with a periodically porous top electrode. The vertical array configuration helps to greatly increase the sensitivity of the sensor while the pores in the top electrode layer significantly improve sensing response times by allowing analyte gases to pass through freely. Herein, we show highly sensitive detection to both nitrogen dioxide (NO(2)) and ammonia (NH(3)) in humidified air. NO(2) detection down to 10 parts per billion (ppb) is demonstrated and an order-of-magnitude improvement in sensor response time is shown in the detection of NH(3).

show abstract

Section: Resultsmentioning

confidence: 99%

Periodically porous top electrodes on vertical nanowire arrays for highly sensitive gas detection

Field

Pehrsson

2011

Nanotechnology

Self Cite

View full text Add to dashboard Cite

show abstract

“…Graphene or reduced graphene oxide (rGO) with high charge carrier mobility, atomically thin nature and abundant adsorption sites, makes the semiconductor/graphene Schottky heterojunction (Barristor) ultrasensitive for gas sensing . Vertical silicon nanowires (SiNWs) array offers distinct merits in terms of the capability for surface functionalization and the sufficient gaps for molecules diffusion, and SiNWs array‐based sensor has been considered an ideal platform for gas sensing due to the higher signal‐to‐noise ratios and faster response . The electron affinity of TiO 2 (4.0 eV) is only a bit smaller than that of silicon (4.05 eV); thus the insertion of TiO 2 into Si/rGO should be an ideal choice to support the above assertion.…”

Section: Introductionmentioning

confidence: 99%

A High‐Performance Nitro‐Explosives Schottky Sensor Boosted by Interface Modulation

Yang

Dou

Zhang

et al. 2015

Adv Funct Materials

View full text Add to dashboard Cite

4039wileyonlinelibrary.com mole cules and depends highly on the analyte concentrations. [8][9][10][11][12] As a result, the traditional Ohm-contacted nanosensor has diffi culty in realizing the ultrasensitive detection in real circumstances where open environment must be considered. Recently, it was demonstrated that Schottky contact could largely improve the sensitivity of nanosensors due to that Schottky barrier serves as a "gate" controlling the current passing through the barrier, [ 13,14 ] and the value of this current highly depends on the Schottky barrier height (SBH). A small change in SBH will lead to a huge change in current, which is the basis of the Schottky barrier enhanced sensing. [ 13 ] The selection of the components of the Schottky junction is of vital importance to improve the sensor performance, which highly depends on the energy band structure and adsorption characteristics. It is reported that a higher SBH favors a better sensitivity in a Schottky-gated sensor toward electron acceptor analytes detection, while for electron donor analytes detection, the result is opposite. [ 15 ] Thus, the insertion of another semiconductor that could both modulate the SBH and increase the adsorption energy will greatly increase the sensitivity and selectivity in a Schottky junction sensor. Graphene or reduced graphene oxide (rGO) with high charge carrier mobility, atomically thin nature and abundant adsorption sites, [16][17][18][19][20] makes the semiconductor/graphene Schottky heterojunction (Barristor) ultrasensitive for gas sensing. [ 21,22 ] Vertical silicon nanowires (SiNWs) array offers distinct merits in terms of the capability for surface functionalization and the suffi cient gaps for molecules diffusion, and SiNWs array-based sensor has been considered an ideal platform for gas sensing due to the higher signal-to-noise ratios and faster response. [ 23,24 ] The electron affi nity of TiO 2 (4.0 eV) is only a bit smaller than that of silicon (4.05 eV); [ 25 ] thus the insertion of TiO 2 into Si/rGO should be an ideal choice to support the above assertion. As a result, the SiNWs array/TiO 2 /rGO ternary junction will provide a new approach for designing ultrasensitive and selective sensors.Nitro-explosives is one of the most important categories in common explosives, and the detection of them has been a research focus due to plenty of adverse events, increasing threat of terrorism attack, and the need for homeland security. [ 1,9,26,27 ] The sensitive, selective, and rapid detection of nitro-explosives vapors is still a challenge due to the low vapor pressure of

show abstract

“…Notably, nanowire-based gas sensors exhibit high sensitivity, short response times, and high stability; in addition, they are lightweight and can operate at lower temperatures than sensors fabricated from their bulk counterparts [9]. Therefore, several nanowire-based gas sensors have been developed [10][11][12][13]. Stannic oxide (SnO 2 ) is one of the most important n-type semiconducting (E g ~ 3.6 eV) metal oxides [14] and has been used in gas sensors [15][16][17].…”

Section: Introductionmentioning

confidence: 99%

“…SnO 2 -Si heterojunction nanowires are promising materials for gas sensing applications. Si-based gas sensors [11] have currently received significant interest for gas sensing because of their…”

Section: Introductionmentioning

confidence: 99%

Low-Temperature H<sub>2</sub>S Sensors Based on Si-Coated SnO<sub>2</sub> Nanowires

Choi¹,

Mirzaei²,

Bang³

et al. 2019

Korean J. Met. Mater.

View full text Add to dashboard Cite

To attain high life standards, it is important to develop high-performance non-toxic gas sensors for public safety, environmental pollutant control, industrial processes, etc. Because reports on single element semiconductor-coated semiconducting metal oxides for sensing applications are rare, we synthesized SnO 2 nanowires and coated them with a 5 nm-thick or 10 nm-thick Si layer for H 2 S gas sensing studies. SnO 2 nanowires were successfully synthesized using a highly pure metallic Sn powder at high temperature in a tube furnace by the vapor-liquid-solid method and Si was deposited on the nanowires by the sputtering technique. The desired morphology and composition of the synthesized nanowires were confirmed by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and energy-dispersive X-ray spectroscopy. Moreover, the gas sensing characteristics of pristine and Si-coated SnO 2 nanowires toward H 2 S, CO, H 2 , C 6 H 6 , C 2 H 5 OH and C 6 H 7 gases were investigated. The sensing results revealed a good response to H 2 S at the optimum operational temperature of 100°C. Notably, Si-coated SnO 2 nanowire sensors showed a better response to H 2 S than pristine SnO 2 nanowires. The mechanism of H 2 S sensing is discussed in detail here. This study shows that the Si coating on the SnO 2 nanowire enhances its sensing performance and decreases the sensing temperature required for H 2 S gas detection.

show abstract

Vapor Detection Performance of Vertically Aligned, Ordered Arrays of Silicon Nanowires with a Porous Electrode

Cited by 28 publications

References 28 publications

Periodically porous top electrodes on vertical nanowire arrays for highly sensitive gas detection

Periodically porous top electrodes on vertical nanowire arrays for highly sensitive gas detection

A High‐Performance Nitro‐Explosives Schottky Sensor Boosted by Interface Modulation

Low-Temperature H<sub>2</sub>S Sensors Based on Si-Coated SnO<sub>2</sub> Nanowires

Contact Info

Product

Resources

About