Strongly Superlinear Light Emission and Large Induced Absorption in Oxidized Porous Silicon Films

1998 ◽  
Vol 536 ◽  
Author(s):  
H. Koyama ◽  
P. M. Fauchet
Keyword(s):  
Porous Silicon ◽  
Thermal Effects ◽  
Light Emission ◽  
Laser Intensity ◽  
Excitation Intensity ◽  
Silicon Films ◽  
Free Standing ◽  
Induced Absorption ◽  
Cw Laser ◽  
Oxidized Porous Silicon

AbstractThe optical properties of oxidized free-standing porous silicon films excited by a cw laser have been investigated. It is found that samples oxidized at 800–950 °C show a strongly superlinear light emission at an excitation intensity of ∼10 W/cm2. This emission has a peak at 900–1100 nm and shows a blueshift as the oxidation temperature is increased. These samples also show a very large induced absorption, where the transmittance is found to decrease reversibly by ≤99.7 %.The induced absorption increases linearly with increasing pump laser intensity. Both the superlinear emission and the large induced absorption are quenched when the samples are attached to materials with a higher thermal conductivity, suggesting that laser-induced thermal effects are responsible for these phenomena.

Laser-induced thermal effects on the optical properties of free-standing porous silicon films

2000 ◽  
Vol 87 (4) ◽  
pp. 1788-1794 ◽  
Author(s):  
Hideki Koyama ◽  
Philippe M. Fauchet
Keyword(s):  
Optical Properties ◽  
Porous Silicon ◽  
Thermal Effects ◽  
Silicon Films ◽  
Free Standing

Bright visible light emission from electro-oxidized porous silicon

1993 ◽  
pp. 593-602
Author(s):  
J.C. Vial ◽  
S. Billat ◽  
A. Bsiesy ◽  
G. Fishman ◽  
F. Gaspard ◽  
...  
Keyword(s):  
Porous Silicon ◽  
Visible Light ◽  
Light Emission ◽  
Oxidized Porous Silicon ◽  
Visible Light Emission

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.

Femtosecond Nonlinear Transmission Study of Free-Standing Porous Silicon Films

1995 ◽  
Vol 405 ◽  
Author(s):  
V. Klimov ◽  
D. Mcbranch ◽  
V. Karavanskii
Keyword(s):  
Porous Silicon ◽  
Transient Absorption ◽  
Energy Levels ◽  
Silicon Films ◽  
Spectral Structure ◽  
Relaxation Dynamics ◽  
Free Standing ◽  
Pump And Probe ◽  
Transmission Study ◽  
Nonlinear Signal

AbstractLarge photo-induced absorption signals were observed in free standing porous silicon films in the spectral range from 1.1 to 2.5 eV using a femtosecond pump and probe technique. The measured nonlinear signal has a very fast component with relaxation constants from 800 fs to tens of picoseconds superimposed on the slow-relaxing thermal background. The spectral structure and relaxation dynamics of the short-lived component of transient absorption show the presence of molecular-like Si complexes with well defined energy levels and spectrally uniform picosecond relaxation dynamics.

Bright visible light emission from electro-oxidized porous silicon

1993 ◽  
Vol 185 (1-4) ◽  
pp. 593-602 ◽  
Author(s):  
J.C. Vial ◽  
S. Billat ◽  
A. Bsiesy ◽  
G. Fishman ◽  
F. Gaspard ◽  
...  
Keyword(s):  
Porous Silicon ◽  
Visible Light ◽  
Light Emission ◽  
Oxidized Porous Silicon ◽  
Visible Light Emission

Mechanisms of visible-light emission from electro-oxidized porous silicon

1992 ◽  
Vol 45 (24) ◽  
pp. 14171-14176 ◽  
Author(s):  
J. C. Vial ◽  
A. Bsiesy ◽  
F. Gaspard ◽  
R. Hérino ◽  
M. Ligeon ◽  
...  
Keyword(s):  
Porous Silicon ◽  
Visible Light ◽  
Light Emission ◽  
Oxidized Porous Silicon ◽  
Visible Light Emission

Absorption and luminescence studies of free-standing porous silicon films

1994 ◽  
Vol 49 (8) ◽  
pp. 5386-5397 ◽  
Author(s):  
Y. H. Xie ◽  
M. S. Hybertsen ◽  
William L. Wilson ◽  
S. A. Ipri ◽  
G. E. Carver ◽  
...  
Keyword(s):  
Porous Silicon ◽  
Silicon Films ◽  
Free Standing

Strongly nonlinear luminescence in oxidized porous silicon films

1998 ◽  
Vol 80 (1-4) ◽  
pp. 99-102 ◽  
Author(s):  
Hideki Koyama ◽  
Leonid Tsybeskov ◽  
Philippe M. Fauchet
Keyword(s):  
Porous Silicon ◽  
Silicon Films ◽  
Strongly Nonlinear ◽  
Oxidized Porous Silicon ◽  
Nonlinear Luminescence

Inelastic light scattering and X-ray diffraction from thick free-standing porous silicon films

1998 ◽  
Vol 80 (1-4) ◽  
pp. 193-198 ◽  
Author(s):  
A.V. Andrianov ◽  
G. Polisski ◽  
J. Morgan ◽  
F. Koch
Keyword(s):  
Light Scattering ◽  
Porous Silicon ◽  
Silicon Films ◽  
X Ray Diffraction ◽  
Free Standing ◽  
X Ray ◽  
Inelastic Light Scattering
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