scholarly journals Enhanced quantum yield of photoluminescent porous silicon prepared by supercritical drying

2016 ◽  
Vol 108 (15) ◽  
pp. 153111 ◽  
Author(s):  
Jinmyoung Joo ◽  
Thomas Defforge ◽  
Armando Loni ◽  
Dokyoung Kim ◽  
Z. Y. Li ◽  
...  
Keyword(s):  
Porous Silicon ◽  
Quantum Yield ◽  
Supercritical Drying

scholarly journals Si/SiO2 Core/Shell Luminescent Silicon Nanocrystals and Porous Silicon Powders With High Quantum Yield, Long Lifetime, and Good Stability

2019 ◽  
Vol 7 ◽  
Author(s):  
Bernard Gelloz ◽  
Firman Bagja Juangsa ◽  
Tomohiro Nozaki ◽  
Koji Asaka ◽  
Nobuyoshi Koshida ◽  
...  
Keyword(s):  
Porous Silicon ◽  
Quantum Yield ◽  
Silicon Nanocrystals ◽  
Good Stability ◽  
Core Shell ◽  
High Quantum Yield ◽  
High Quantum ◽  
Long Lifetime

scholarly journals Towards Porous Silicon Oxycarbide Materials: Effects of Solvents on Microstructural Features of Poly(methylhydrosiloxane)/Divynilbenzene Aerogels

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2589 ◽  
Author(s):  
Susana Aguirre-Medel ◽  
Prasanta Jana ◽  
Peter Kroll ◽  
Gian Sorarù
Keyword(s):  
Porous Silicon ◽  
Pore Formation ◽  
Supercritical Drying ◽  
Silicon Oxycarbide ◽  
Cross Linking ◽  
Solvent Exchange ◽  
Hydrosilylation Reaction ◽  
Liquid Co2 ◽  
Major Factors ◽  
The Impact

We investigate the impact of solvents on the microstructure of poly(methylhydrosiloxane)/divinylbenzene (PMHS/DVB) aerogels. The gels are obtained in highly diluted conditions via hydrosilylation reaction of PMHS bearing Si-H groups and cross-linking it with C=C groups of DVB. Polymer aerogels are obtained after solvent exchange with liquid CO2 and subsequent supercritical drying. Samples are characterized using microscopy and porosimetry. Common pore-formation concepts do not provide a solid rationale for the observed data. We postulate that solubility and swelling of the cross-linked polymer in various solvents are major factors governing pore formation of these PMHS/DVB polymer aerogels.

Optical Properties of Free-Standing Ultrahigh Porosity Silicon Films Prepared by Supercritical Drying

1996 ◽  
Vol 452 ◽  
Author(s):  
J. Von Behren ◽  
P. M. Fauchet ◽  
E. H. Chimowitz ◽  
C. T. Lira
Keyword(s):  
Porous Silicon ◽  
Electrochemical Etching ◽  
Supercritical Drying ◽  
Silicon Films ◽  
Index Of Refraction ◽  
Free Standing ◽  
Crystal Silicon ◽  
Si Substrates ◽  
Type C ◽  
P Type

AbstractHighly luminescent free-standing porous silicon thin films of excellent optical quality have been manufactured by using electrochemical etching and lift-off steps combined with supercritical drying. One to 50 μm thick free-standing layers made from highly (p+) and moderately (p) Boron doped single crystal silicon (c-Si) substrates have been produced with porosities (P) up to 95 %. The Fabry-Pérot fringes observed in the transmission and photoluminescence (PL) spectra are used to determine the refractive index. At the highest P the index of refraction is below 1.2 from the IR to 2 eV. The absorption coefficients follow a nearly exponential behavior in the energy range from 1.2 eV and 4 eV. The porosity corrected absorption spectra of free-standing films made from p type c-Si substrates are blue shifted with respect to those prepared from p+ substrates. For P > 70 % a blue shift is also observed in PL. At equal porosities the luminescence intensities of porous silicon films made from p+ and p type c-Si are different by one order of magnitude.

Formation of Intensive Photoluminescence in Porous Silicon

1995 ◽  
Vol 405 ◽  
Author(s):  
V. A. Makara ◽  
M. S. Boltovets ◽  
O. V. Vakulenko ◽  
O. I. Datsenko ◽  
O. V. Rudenko
Keyword(s):  
Porous Silicon ◽  
Quantum Yield ◽  
Rhodamine 6G ◽  
Mechanical Stresses ◽  
Pl Spectra ◽  
Pl Intensity

AbstractPhotoluminescence (PL) spectra of porous silicon (PS) samples are studied. Effect of mechanical stresses in substrate on PL intensity is shown. The quantum yield (QY) of PS luminescence is estimated by comparing PL spectra of PS and rhodamine 6G.

scholarly journals ЭПР и люминесценция пористого кремния

2021 ◽  
Vol 63 (3) ◽  
pp. 370
Author(s):  
Н.Е. Демидова ◽  
Е.С. Демидов ◽  
В.В. Карзанов
Keyword(s):  
Porous Silicon ◽  
Quantum Yield ◽  
Thermal Annealing ◽  
Chemical Oxidation ◽  
Research Data ◽  
Maximum Quantum Yield ◽  
Nonmonotonic Dependence

There are presented research data of ESR, photoluminescence (PL) and carrent transport in porous silicon (PS) on KDB-0.3 and KES-0.01 Si, oxidized by10 minute isochronous thermal annealing on air at temperatures Tann from 20°С to 900°С and also in HNO3 for the purpose of the further clearing of Pb - centres nature of no radiating recombination. Maximum quantum yield of PL was observed at chemical oxidation of the PS on silicon of KDB-0.3 mark.. Anticorrelation of PL and ESR intensities of Pb - centres in the range of Tann = (20-300) °С takes a place. . Nonmonotonic dependence of ESR intensity of Pb - centres vs Tann with a minimum nearby 700°С is found out. Weak PL in PS with Tann nearby 700°С at minimum of ESR of Pb - centres means occurrence with annealing of other no radiating recombination centres. Falling of conductivity of PS with growth of Tann is connected with disintegration of Si fibres in Ps on small granules through which there is a discrete tunneling of current carriers.

Preparation, Properties and Applications of Free-Standing Porous Silicon Films

1994 ◽  
Vol 358 ◽  
Author(s):  
J. Von Behren ◽  
L. Tsybeskov ◽  
P. M. Fauchet
Keyword(s):  
Porous Silicon ◽  
Near Infrared ◽  
Electrochemical Etching ◽  
Supercritical Drying ◽  
Silicon Films ◽  
Index Of Refraction ◽  
High Porosity ◽  
Large Area ◽  
Free Standing ◽  
Lift Off

ABSTRACTUsing special electrochemical etching and lift-off steps, we have fabricated large-area freestanding porous silicon films in the thickness range from 0.1 μm to 50 μm. Their transmission is near 100% in the near infrared which is indicative of very high porosity/low index of refraction films. These optically flat and homogeneous films exhibit no surface and bulk scattering, despite the fact that they did not undergo supercritical drying. The relationship between the absorption coefficient, the luminescence spectrum, and the chemical and structural properties is examined as a function of preparation and post-treatment conditions. Because of their superior optical properties, these films are suitable for many device applications.

Calculation of exchange energy in quantum dots : application to porous silicon

1993 ◽  
Vol 03 (C5) ◽  
pp. 355-358 ◽  
Author(s):  
G. FISHMAN ◽  
R. ROMESTAIN ◽  
J. C. VIAL
Keyword(s):  
Quantum Dots ◽  
Porous Silicon ◽  
Exchange Energy

ANTI-REFLECTIVE PROPERTIES OF GRADIENT-POROUS SILICON

2017 ◽  
pp. 16-25
Author(s):  
E. A. Gosteva ◽  
V. V. Starkov ◽  
Yu. N. Parhomenko ◽  
M. O. Kah ◽  
I. A. Iwe
Keyword(s):  
Porous Silicon

Investigation of Porous Silicon/Carbon Composite as Anodes for Lithium Ion Batteries

2015 ◽  
Vol 30 (4) ◽  
pp. 351 ◽  
Author(s):  
HUANG Yan-Hua ◽  
HAN Xiang ◽  
CHEN Hui-Xin ◽  
CHEN Song-Yan ◽  
YANG Yong
Keyword(s):  
Porous Silicon ◽  
Lithium Ion Batteries ◽  
Lithium Ion ◽  
Carbon Composite ◽  
Silicon Carbon
Sign in / Sign up

Export Citation Format

Share Document