Room-Temperature Carbide-Derived Carbon Synthesis by Electrochemical Etching of MAX Phases

AbstractNanopore covered microporous silicon conductometric gas sensors have been produced via electrochemical etching and standard microfabrication techniques. Reversible and sensitive gas sensors working at room temperature have been fabricated. Sensing of NH3, NOx and PH3 at or below the ppm level have been achieved. The porous silicon (PS) surface has been modified using selective coatings including electroless tin, gold, nickel and copper solutions to increase the response to NOx, NH3, and PH3 respectively. The diffusion of the analyte species has been investigated in the nanopore and micropore regimes by numerical analysis. Comparing the response time of the hybrid porous sensor surface with numerical diffusion calculations on the pores, it has been observed that Knudsen diffusion time scales dominate the sensor response. A transduction model is proposed based on nanopore limited gas diffusion and the experimental response and recovery data.

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Bulk-heterojunction Based on Blending of Red and Blue Luminescent Silicon Nanocrystals and P3HT Polymer

MRS Proceedings ◽

10.1557/proc-1153-a15-02 ◽

2009 ◽

Vol 1153 ◽

Author(s):

Vladimir Švrček ◽

Michio Kondo

Keyword(s):

Laser Ablation ◽

Transport Properties ◽

Conjugated Polymer ◽

Silicon Nanocrystals ◽

Room Temperature ◽

Electrochemical Etching ◽

Bulk Heterojunction ◽

Dark Conductivity ◽

Ambient Conditions ◽

Parallel Configuration

AbstractBlending of red and blue photoluminescent silicon nanocrystals (Si-ncs) with poly(3-hexylthiophene (P3HT) conjugated polymer is demonstrated. The room temperature luminescent and ambient conditions stable Si-ncs prepared by electrochemical etching and laser ablation in water are used for the blend fabrication. Furthermore photo-electric properties in parallel configuration on platinum interdugitated contact are shown. Both types of Si-ncs results the bulk-heterojunction formation and photoconductivity is observed when the blends are irradiated AM1.5. The increase in photoconductivity is rather the same and ratio between photo- and dark-conductivity is about 1.7. The nanocrystal oxidation during laser ablation fabrication process in water hinders the transport properties of the blend.

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Raman Scattering in Electrochemically Prepared Porous Silicon

MRS Proceedings ◽

10.1557/proc-256-69 ◽

1991 ◽

Vol 256 ◽

Cited By ~ 3

Author(s):

Y. -J. Wu ◽

X. -S. Zhao ◽

P. D. Persans

Keyword(s):

Porous Silicon ◽

Raman Scattering ◽

Amorphous Silicon ◽

Room Temperature ◽

High Efficiency ◽

Silicon Oxide ◽

Electrochemical Etching ◽

Visible Range ◽

Microcrystalline Silicon ◽

Hydrogenated Amorphous

ABSTRACTPorous silicon of various porosity has been prepared by electrochemical etching of silicon with different doping levels. Room temperature photoluminescence in the visible range is observed from the powder scraped from the top layer of the etched samples. In this paper we use Raman scattering to characterize the source of the high efficiency photoluminescence. We have also studied microcrystalline silicon prepared by thermal annealing of hydrogenated amorphous silicon/amorphous silicon oxide multilayers.

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Room-Temperature H2 Gas Sensing Characterization of Graphene-Doped Porous Silicon via a Facile Solution Dropping Method

10.20944/preprints201710.0106.v1 ◽

2017 ◽

Author(s):

Nu Si A Eom ◽

Hong-Baek Cho ◽

Yoseb Song ◽

Woojin Lee ◽

Tohru Sekino ◽

...

Keyword(s):

Porous Silicon ◽

Gas Sensor ◽

Room Temperature ◽

Gas Sensing ◽

Electrochemical Etching ◽

Sensor Material ◽

Sensing Mechanism ◽

Si Substrates ◽

H2 Sensor ◽

P Type

In this study, a graphene-doped porous silicon (G-doped/p-Si) substrate for low ppm H2 gas detection by an inexpensive synthesis route was proposed as a potential noble graphene-based gas sensor material and to understand the sensing mechanism. The G-doped/p-Si gas sensor was synthesized by a simple capillary force-assisted solution dropping method on p-Si substrates, whose porosity was generated through an electrochemical etching process. G-doped/p-Si was fabricated with various graphene concentrations and exploited as a H2 sensor operated at room temperature. The sensing mechanism of the sensor with/without graphene decoration on p-Si was proposed to elucidate the synergetic gas sensing effect generated from the interface between the graphene and p-type silicon.

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