Mechanism of in-Situ Photoluminescence Decay in Porous Silicon and its Application to Maskless Patterning

1992 ◽  
Vol 283 ◽  
Author(s):  
Mikio Takai ◽  
Sanae Indou ◽  
Hisanori Murase
Keyword(s):  
Porous Silicon ◽  
Laser Beam ◽  
Time Scale ◽  
Excitation Intensity ◽  
Porous Si ◽  
Photoluminescence Decay ◽  
Enhanced Oxidation ◽  
Maskless Patterning

ABSTRACTPL decay in a time scale of ms for fresh porous Si surfaces was investigated for different atmospheres and excitation intensities to clarify the mechanism of the PL decay. The PL excitation intensity and atmosphere were found to affect the decay of PL, which was due to laser enhanced oxidation.Locally PL excited areas of porous Si were also found to be etched in a HF solution. Maskless patterning using this effect could be performed by a scan of a focused laser beam followed by HF etching.

scholarly journals In situ metalation of free base phthalocyanine covalently bonded to silicon surfaces

2014 ◽  
Vol 5 ◽  
pp. 2222-2229 ◽  
Author(s):  
Fabio Lupo ◽  
Cristina Tudisco ◽  
Federico Bertani ◽  
Enrico Dalcanale ◽  
Guglielmo G Condorelli
Keyword(s):  
Porous Silicon ◽  
Photoelectron Spectroscopy ◽  
Relevant Information ◽  
Silicon Surfaces ◽  
Porous Si ◽  
Wet Chemistry ◽  
X Ray ◽  
Covalently Bonded ◽  
Phthalocyanine Ring

Free 4-undecenoxyphthalocyanine molecules were covalently bonded to Si(100) and porous silicon through thermic hydrosilylation of the terminal double bonds of the undecenyl chains. The success of the anchoring strategy on both surfaces was demonstrated by the combination of X-ray photoelectron spectroscopy with control experiments performed adopting the commercially available 2,3,9,10,16,17,23,24-octakis(octyloxy)-29H,31H-phthalocyanine, which is not suited for silicon anchoring. Moreover, the study of the shape of the XPS N 1s band gave relevant information on the interactions occurring between the anchored molecules and the substrates. The spectra suggest that the phthalocyanine ring interacts significantly with the flat Si surface, whilst ring–surface interactions are less relevant on porous Si. The surface-bonded molecules were then metalated in situ with Co by using wet chemistry. The efficiency of the metalation process was evaluated by XPS measurements and, in particular, on porous silicon, the complexation of cobalt was confirmed by the disappearance in the FTIR spectra of the band at 3290 cm−1 due to –NH stretches. Finally, XPS results revealed that the different surface–phthalocyanine interactions observed for flat and porous substrates affect the efficiency of the in situ metalation process.

An Alternate Mechanism for Porous Si Photoluminescence: Recombination in SiHx Complexes

1991 ◽  
Vol 256 ◽  
Author(s):  
S. M. Prokes ◽  
O. J. Glembocki ◽  
V. M. Bermudez ◽  
R. Kaplan ◽  
L. E. Friedersdorf ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Porous Silicon ◽  
Hydrogen Content ◽  
Hydrogen Desorption ◽  
Porous Si ◽  
Temperature Range ◽  
Silicon Hydrides ◽  
Alternate Mechanism ◽  
Pl Intensity

ABSTRACTPorous silicon layers have been formed which exhibit photoluminescence (PL) peaks that do not blueshift with increasing porosity. Hydrogen desorption experiments have been performed in vacuum under anneals between 230°C–390°C. Simultaneous, in-situ PL measurements show that the PL intensity decreases and disappears with decreasing hydrogen content. Infrared spectroscopy (IR) measurements also show loss of hydride species in the same temperature range. These results indicate that hydrogen is important in the PL process. We suggest that silicon hydrides are the source of PL in porous SI.

scholarly journals Carbon Particle In-Situ Alloying of the Case-Hardening Steel 16MnCr5 in Laser Powder Bed Fusion

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 896
Author(s):  
Matthias Schmitt ◽  
Albin Gottwalt ◽  
Jakob Winkler ◽  
Thomas Tobie ◽  
Georg Schlick ◽  
...  
Keyword(s):  
Laser Beam ◽  
Mechanical Strength ◽  
Carbon Content ◽  
Metal Powder ◽  
Case Hardening ◽  
Powder Bed Fusion ◽  
Powder Bed ◽  
Carbon Particles ◽  
Case Hardening Steel

The carbon content of steel affects many of its essential properties, e.g., hardness and mechanical strength. In the powder bed fusion process of metals using a laser beam (PBF-LB/M), usually, pre-alloyed metal powder is solidified layer-by-layer using a laser beam to create parts. A reduction of the carbon content in steels is observed during this process. This study examines adding carbon particles to the metal powder and in situ alloying in the PBF-LB/M process as a countermeasure. Suitable carbon particles are selected and their effect on the particle size distribution and homogeneity of the mixtures is analysed. The workability in PBF-LB is then shown. This is followed by an evaluation of the resulting mechanical properties (hardness and mechanical strength) and microstructure in the as-built state and the state after heat treatment. Furthermore, potential use cases like multi-material or functionally graded parts are discussed.

Comment on ‘‘In situ photoluminescence spectral study of porous Si in HF aqueous solution’’ [Appl. Phys. Lett. 65, 1653 (1994)]

1995 ◽  
Vol 66 (21) ◽  
pp. 2912-2913 ◽  
Author(s):  
M. Davison ◽  
K. P. O’Donnell ◽  
U. M. Noor ◽  
D. Uttamchandani ◽  
L. E. A. Berlouis
Keyword(s):  
Aqueous Solution ◽  
Spectral Study ◽  
Porous Si

Three-Dimensional Porous Si and SiO2 with In Situ Decorated Carbon Nanotubes As Anode Materials for Li-ion Batteries

2017 ◽  
Vol 9 (21) ◽  
pp. 17807-17813 ◽  
Author(s):  
Junming Su ◽  
Jiayue Zhao ◽  
Liangyu Li ◽  
Congcong Zhang ◽  
Chunguang Chen ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Anode Materials ◽  
Three Dimensional ◽  
Li Ion Batteries ◽  
Porous Si ◽  
Li Ion

A novel 3D porous electrode of polyaniline and PEDOT:PSS coated SiNWs for low-cost and high-performance supercapacitors

2021 ◽  
Author(s):  
Xiaojuan Shen ◽  
Xuan Zhang ◽  
Tongfei Wang ◽  
Songjun Li ◽  
Zhaoqiang Li
Keyword(s):  
High Performance ◽  
Solution Method ◽  
In Situ Polymerization ◽  
Low Cost ◽  
Porous Electrode ◽  
Simple Solution ◽  
Porous Si ◽  
Supercapacitor Electrode

In this study, a novel 3D porous Si-based supercapacitor electrode was developed by the simple solution method, which involved firstly the in-situ polymerization of polyaniline particles (PANI) on the Si...

Enhancement of efficiency in graphene/porous silicon solar cells by co-doping graphene with gold nanoparticles and bis(trifluoromethanesulfonyl)-amide

2017 ◽  
Vol 5 (35) ◽  
pp. 9005-9011 ◽  
Author(s):  
Ju Hwan Kim ◽  
Dong Hee Shin ◽  
Ha Seung Lee ◽  
Chan Wook Jang ◽  
Jong Min Kim ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Solar Cells ◽  
Porous Silicon ◽  
Au Nanoparticles ◽  
Silicon Solar Cells ◽  
Porous Si ◽  
Co Doping ◽  
Si Solar Cells ◽  
First Time

The co-doping of graphene with Au nanoparticles and bis(trifluoromethanesulfonyl)-amide is employed for the first time to enhance the performance of graphene/porous Si solar cells.

Sign in / Sign up

Export Citation Format

Share Document