Optical properties and luminescence mechanism of oxidized free-standing porous silicon films

1999 ◽  
Vol 86 (4) ◽  
pp. 2066-2072 ◽  
Author(s):  
Dongsheng Xu ◽  
Guolin Guo ◽  
Linlin Gui ◽  
Youqi Tang ◽  
B. R. Zhang ◽  
...  
Keyword(s):  
Optical Properties ◽  
Porous Silicon ◽  
Silicon Films ◽  
Free Standing

Investigation of optical properties of free-standing porous silicon films by absorption and mirage effect

1993 ◽  
Vol 57 (1-6) ◽  
pp. 217-221 ◽  
Author(s):  
G. Vincent ◽  
F. Leblanc ◽  
I. Sagnes ◽  
P.A. Badoz ◽  
A. Halimaoui
Keyword(s):  
Optical Properties ◽  
Porous Silicon ◽  
Silicon Films ◽  
Free Standing ◽  
Mirage Effect

scholarly journals Microstructure and optical properties of free-standing porous silicon films: Size dependence of absorption spectra in Si nanometer-sized crystallites

1993 ◽  
Vol 48 (4) ◽  
pp. 2827-2830 ◽  
Author(s):  
Yoshihiko Kanemitsu ◽  
Hiroshi Uto ◽  
Yasuaki Masumoto ◽  
Takahiro Matsumoto ◽  
Toshiro Futagi ◽  
...  
Keyword(s):  
Optical Properties ◽  
Porous Silicon ◽  
Absorption Spectra ◽  
Size Dependence ◽  
Silicon Films ◽  
Free Standing

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.

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.

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

Dispersive Fourier Transform Spectroscopy Of Free-Standing Porous Silicon Films

1997 ◽  
Vol 486 ◽  
Author(s):  
J. Salonen ◽  
K. Saarinen ◽  
J. Peura ◽  
J. Vilnikanoja ◽  
I. Salomaa ◽  
...  
Keyword(s):  
Refractive Index ◽  
Fourier Transform ◽  
Porous Silicon ◽  
Absorption Coefficient ◽  
Optical Constants ◽  
Fourier Transform Spectroscopy ◽  
Silicon Films ◽  
Spectral Variation ◽  
Free Standing ◽  
Dispersive Fourier Transform Spectroscopy

AbstractWe have investigated optical constants of free-standing porous silicon films by dispersive Fourier transform spectroscopy (DFTS) in the NIR-VIS range. This allows the spectral variation of both the absorption coefficient and the refractive index of a material to be determined from the measurements of the attenuation and phase shift imposed on an electromagnetic wave by its interaction with a specimen. Using these optical constants, we have studied the complex dielectric function and the complex conductivity. To avoid the additive error in the absorption spectra arising from the pseudocoherence, we measured the transmission spectra by conventional Fourier transform spectroscopy (FTS). Using the refraction spectrum derived from the DFTS measurements, we have corrected for reflection losses in calculation of the absorption spectrum from the FTS transmission spectrum. The changes in the absorption coefficient and the refractive index due to oxidation, which is the most common aging phenomenon in porous silicon, have been studied using samples with different types of oxidization.

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