Studies on Chemical Modification of Porous Silicon-Based Graded-Index Optical Microcavities for Improved Stability Under Alkaline Conditions

2012 ◽  
Vol 22 (18) ◽  
pp. 3890-3898 ◽  
Author(s):  
T. Jalkanen ◽  
E. Mäkilä ◽  
Y.-I. Suzuki ◽  
T. Urata ◽  
K. Fukami ◽  
...  
Keyword(s):  
Porous Silicon ◽  
Chemical Modification ◽  
Graded Index ◽  
Optical Microcavities ◽  
Alkaline Conditions ◽  
Improved Stability ◽  
Silicon Based

Stabilization of Porous Silicon Free-Standing Coupled Optical Microcavities by Surface Chemical Modification

2019 ◽  
Vol 16 (3) ◽  
pp. 211-219 ◽  
Author(s):  
Bernard Gelloz ◽  
Kouichiro Murata ◽  
Toshiyuki Ohta ◽  
Mher Ghulinyan ◽  
Lorenzo Pavesi ◽  
...  
Keyword(s):  
Porous Silicon ◽  
Chemical Modification ◽  
Surface Chemical ◽  
Free Standing ◽  
Optical Microcavities ◽  
Surface Chemical Modification

Photoconductivity in Vacuum Deposited Films of Silicon-Based Polymers

1996 ◽  
Vol 444 ◽  
Author(s):  
H. Okumoto ◽  
M. Shimomura ◽  
N. Minami ◽  
Y. Tanabe
Keyword(s):  
Charge Transfer ◽  
Chemical Modification ◽  
Electronic Transport ◽  
Hole Transport ◽  
Electron Acceptors ◽  
Oxygen Atmosphere ◽  
Dangling Bonds ◽  
Silicon Based ◽  
Deposited Films

AbstractSilicon-based polymers with σconjugated electrons have specific properties; photoreactivity for microlithography and photoconductivity for hole transport materials. To explore the possibility of combining these two properties to develop photoresists with electronic transport capability, photoconductivity of polysilanes is investigated in connection with their photoinduced chemical modification. Increase in photocurrent is observed accompanying photoreaction of poly(dimethylsilane) vacuum deposited films. This increase is found to be greatly enhanced in oxygen atmosphere. Such changes of photocurrent can be explained by charge transfer to electron acceptors from Si dangling bonds postulated to be formed during photoreaction.

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

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.

Chemical Modification of the Porous Silicon Surface

1994 ◽  
Vol 358 ◽  
Author(s):  
Eric J. Lee ◽  
James S. Ha ◽  
Michael J. Sailor
Keyword(s):  
Porous Silicon ◽  
Chemical Modification ◽  
Formic Acid ◽  
Gas Phase ◽  
Silicon Surface ◽  
Chemical Vapor ◽  
Luminescence Quenching ◽  
Porous Silicon Surface ◽  
Phase Water ◽  
Surface Modified

ABSTRACTThe porous silicon (PS) surface is derivatized with ethanol, triethylsilanol and formic acid as well as oxidized with water. The two reactions used to prepare these surfaces are discussed, and FTIR spectra of the products are presented. Surface-modified PS retains 10-40% of its original photoluminescence. PS-derivatives display reversible luminescence quenching by gas phase water, ethanol, acetonitrile and benzene. The extent of quenching varies with different PS-derivatives depending on the interaction of the chemical vapor with the modified PS surfaces.

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
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