Optical porous-silicon-based sensors with chemically modified surface for detection of organic vapors

2003 ◽  
Author(s):  
T. Chvojka ◽  
T. Holec ◽  
I. Jelinek ◽  
I. Nemec ◽  
J. Jindrich ◽  
...  
Keyword(s):  
Porous Silicon ◽  
Organic Vapors ◽  
Chemically Modified ◽  
Modified Surface ◽  
Silicon Based

scholarly journals Porous Silicon Based Sensor for Organic Vapors

2015 ◽  
Vol 127 (4) ◽  
pp. 1400-1402 ◽  
Author(s):  
E. Kayahan ◽  
Z.B. Bahsi ◽  
A.Y. Oral ◽  
M. Sezer
Keyword(s):  
Porous Silicon ◽  
Organic Vapors ◽  
Silicon Based

scholarly journals Fabrication of Porous Silicon Based Humidity Sensing Elements on Paper

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Tero Jalkanen ◽  
Anni Määttänen ◽  
Ermei Mäkilä ◽  
Jaani Tuura ◽  
Martti Kaasalainen ◽  
...  
Keyword(s):  
Porous Silicon ◽  
Smart Cities ◽  
Low Cost ◽  
Electrical Characterization ◽  
Fabrication Process ◽  
Sensing Element ◽  
Paper Substrate ◽  
Roll To Roll ◽  
Silver Electrodes ◽  
Silicon Based

A roll-to-roll compatible fabrication process of porous silicon (pSi) based sensing elements for a real-time humidity monitoring is described. The sensing elements, consisting of printed interdigitated silver electrodes and a spray-coated pSi layer, were fabricated on a coated paper substrate by a two-step process. Capacitive and resistive responses of the sensing elements were examined under different concentrations of humidity. More than a three orders of magnitude reproducible decrease in resistance was measured when the relative humidity (RH) was increased from 0% to 90%. A relatively fast recovery without the need of any refreshing methods was observed with a change in RH. Humidity background signal and hysteresis arising from the paper substrate were dependent on the thickness of sensing pSi layer. Hysteresis in most optimal sensing element setup (a thick pSi layer) was still noticeable but not detrimental for the sensing. In addition to electrical characterization of sensing elements, thermal degradation and moisture adsorption properties of the paper substrate were examined in connection to the fabrication process of the silver electrodes and the moisture sensitivity of the paper. The results pave the way towards the development of low-cost humidity sensors which could be utilized, for example, in smart packaging applications or in smart cities to monitor the environment.

Porous silicon–based MEMS

2010 ◽  
pp. 481-502
Author(s):  
Gerhard Müller ◽  
Alois Friedberger ◽  
Kathrin Knese
Keyword(s):  
Porous Silicon ◽  
Silicon Based

Porous Silicon-Based Photonic Biosensors: Current Status and Emerging Applications

2018 ◽  
Vol 91 (1) ◽  
pp. 441-467 ◽  
Author(s):  
Sofia Arshavsky-Graham ◽  
Naama Massad-Ivanir ◽  
Ester Segal ◽  
Sharon Weiss
Keyword(s):  
Porous Silicon ◽  
Current Status ◽  
Silicon Based ◽  
Photonic Biosensors

scholarly journals Environmental assessment of contaminants in a downstream area of a landfill

2017 ◽  
Vol 47 (2) ◽  
pp. 972
Author(s):  
E. Koutsopoulou ◽  
K. Katsanou ◽  
D. Papoulis ◽  
E. Zagana ◽  
P. Tsolis- Katagas
Keyword(s):  
Waste Disposal ◽  
Surface Runoff ◽  
Heavy Metal Contamination ◽  
Environmental Risks ◽  
Disposal Site ◽  
Waste Disposal Site ◽  
Chemically Modified ◽  
Modified Surface ◽  
Downstream Area ◽  
Surface Water Samples

Therefore, the evaluation of environmental risks associated with a landfill and the effect of landfill surface runoff was investigated. Soil samples were collected in the downstream area of the waste disposal site and their mineralogy was studied. An appraisal of the heavy metal contamination in the area was attempted. Top layers of sediments seem to interact with chemically modified surface runoff waters from the landfill. Heavy metals such as As and Pb were in significant concentrations in the sediments within a distance of 200 m from the site. Anions such as chloride, sulphate and phosphate adsorbed on clay minerals suggest the interaction of sediments with surface runoff from the waste disposal site. Inorganic parameters NH4 + and NO2 - in surface water samples are above or slightly below the guidelines recommended by EE and WHO. The results indicated that environmental monitoring of the landfill is considered essential.

Photovoltaic Characterization of Trapping in Porous Silicon

1994 ◽  
Vol 358 ◽  
Author(s):  
D. W. Boeringer ◽  
R. Tsu
Keyword(s):  
Porous Silicon ◽  
Photovoltaic Effect ◽  
Light Spot ◽  
Dangling Bond ◽  
Photogenerated Electrons ◽  
Device Applications ◽  
Photovoltaic Characterization ◽  
P Type ◽  
Silicon Based ◽  
Position Sensitive Detectors

ABSTRACTWe report the first observation of the lateral photovoltaic effect in porous silicon. Contacts placed on either side of a porous silicon region develop a voltage up to several millivolts if the sample is asymmetrically illuminated. If the light spot is closer to one contact, the voltage will have one polarity; if it is closer to the other contact, the polarity will be opposite. In the case of n-type, the contact nearest the light spot is positive; for p-type, the contact nearest the light spot is negative In the region between the contacts, the photovoltage varies almost linearly with the position of the light spot, over a distance 4.5 cm across. The origin of our lateral photoeffect may be explained by the trapping of photoexcited carriers by a pair of dangling bond centers in porous silicon. In the case of p-type, the photogenerated electrons are trapped by the dangling bond states while holes diffuse away in the substrate. The situation for n-type is opposite; holes are trapped by the dangling bond states while electrons diffuse away in the substrate. This differs from the conventional lateral photoeffect, which arises under the nonuniform illumination of a junction between two layers of differing conductivities. Hamamatsu sells silicon-based position-sensitive detectors with a resolution down to 0.1 µm. The possibility of using this lateral photoeffect to characterize these dangling bond states in porous silicon as well as several possible device applications will be discussed.

Porous silicon based β-FeSi2 and photoluminescence

2009 ◽  
Vol 97 (3) ◽  
pp. 725-728 ◽  
Author(s):  
H. T. Chen ◽  
X. L. Wu ◽  
Y. Y. Zhang ◽  
W. N. Su
Keyword(s):  
Porous Silicon ◽  
Silicon Based

Fabrication and performance of a superhydrophobic fluorine-modified porous silicon based on photocatalytic hydrosilylation

2021 ◽  
pp. 111561
Author(s):  
Xiaomei Miao ◽  
Keyu Mao ◽  
Yue Yan ◽  
Yongbing Pei ◽  
Michael J. Sailor ◽  
...  
Keyword(s):  
Porous Silicon ◽  
And Performance ◽  
Silicon Based
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