Light emission of C60 embedded in porous silicon

1995 ◽  
Vol 67 (6) ◽  
pp. 783-785 ◽  
Author(s):  
Shen‐Yi Wang ◽  
Wen‐Zhong Shen ◽  
Xue‐Chu Shen ◽  
Lei Zhu ◽  
Zhong‐Min Ren ◽  
...  
Keyword(s):  
Porous Silicon ◽  
Light Emission

Light Emission from Microcrystalline Si Confined in SiO2Matrix through Partial Oxidation of Anodized Porous Silicon

1992 ◽  
Vol 31 (Part 2, No.1A/B) ◽  
pp. L1-L3 ◽  
Author(s):  
Toshimichi Ito ◽  
Toshimichi Ohta ◽  
Akio Hiraki
Keyword(s):  
Porous Silicon ◽  
Partial Oxidation ◽  
Light Emission

Photoluminescence of Sm doped porous silicon—evidence for light emission through luminescence centers in SiO2layers

1994 ◽  
Vol 64 (24) ◽  
pp. 3282-3284 ◽  
Author(s):  
J. Lin ◽  
L. Z. Zhang ◽  
Y. M. Huang ◽  
B. R. Zhang ◽  
G. G. Qin
Keyword(s):  
Porous Silicon ◽  
Light Emission ◽  
Luminescence Centers

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.

LUMINESCENCE BEHAVIOR AND MECHANISM OF LIGHT-EMITTING POROUS SILICON

1994 ◽  
Vol 08 (02) ◽  
pp. 69-92 ◽  
Author(s):  
XUN WANG
Keyword(s):  
Porous Silicon ◽  
Blue Light ◽  
Light Emission ◽  
Energy State ◽  
Surface Recombination Velocity ◽  
Luminescence Spectroscopy ◽  
Carrier Injection ◽  
Blue Light Emission ◽  
Light Emitting ◽  
Si Nanostructures

In this review article, we give a new insight into the luminescence mechanism of porous silicon. First, we observed a “pinning” characteristic of photoluminescent peaks for as-etched porous silicon samples. It was explained as resulting from the discontinuous variation of the size of Si nanostructures, i.e. the size quantization. A tight-binding calculation of the energy band gap widening versus the dimension of nanoscale Si based on the closed-shell Si cluster model agrees well with the experimental observations. Second, the blue-light emission from porous silicon was achieved by using boiling water treatment. By investigating the luminescence micrographic images and the decaying behaviors of PL spectra, it has been shown that the blue-light emission is believed to be originated from the porous silicon skeleton rather than the surface contaminations. The conditions for achieving blue light need proper size of Si nanostructures, low-surface recombination velocity, and mechanically strong skeleton. The fulfillment of these conditions simultaneously is possible but rather critical. Third, the exciton dynamics in light-emitting porous silicon is studied by using the temperature-dependent and picosecond time-resolved luminescence spectroscopy. A direct evidence of the existence of confined excitons induced by the quantum size effect has been revealed. Two excitation states are found to be responsible for the visible light emission, i.e. a higher lying energy state corresponding to the confined excitons in Si nanostructures and a lower lying state related with surfaces of Si wires or dots. A picture of the carrier transfer between the quantum confined state and the surface localized state has been proposed. Finally, we investigated the transient electroluminescence behaviors of Au/porous silicon/Si/Al structure and found it is very similar to that of an ordinary p-n junction light-emitting diode. The mechanism of electroluminescence is explained as the carrier injection through the Au/porous silicon Schotky barrier and the porous silicon/p-Si heterojunction into the corrugated Si wires, where the radiative recombination of carriers occurs.

Structural, Surface Morphological and Photoluminescence Properties of Nanostructured Porous Silicon Material for Optoelectronics Application

2012 ◽  
Vol 584 ◽  
pp. 290-294 ◽  
Author(s):  
Jeyaprakash Pandiarajan ◽  
Natarajan Jeyakumaran ◽  
Natarajan Prithivikumaran
Keyword(s):  
Porous Silicon ◽  
Current Density ◽  
Light Emission ◽  
Electrochemical Etching ◽  
Light Emitting Diode ◽  
Radiative Transition ◽  
Sem Images ◽  
Optoelectronic Application ◽  
Gap Opening ◽  
P Type

The promotion of silicon (Si) from being the key material for microelectronics to an interesting material for optoelectronic application is a consequence of the possibility to reduce its device dimensionally by a cheap and easy technique. In fact, electrochemical etching of Si under controlled conditions leads to the formation of nanocrystalline porous silicon (PS) where quantum confinement of photo excited carriers and surface species yield to a band gap opening and an increased radiative transition rate resulting in efficient light emission. In the present study, the nanostructured PS samples were prepared using anodic etching of p-type silicon. The effect of current density on structural and optical properties of PS, has been investigated. XRD studies confirm the presence of silicon nanocrystallites in the PS structure. By increasing the current density, the average estimated values of grain size are found to be decreased. SEM images indicate that the pores are surrounded by a thick columnar network of silicon walls. The observed PL spectra at room temperature for all the current densities confirm the formation of PS structures with nanocrystalline features. PL studies reveal that there is a prominent visible emission peak at 606 nm. The obtained variation of intensity in PL emission may be used for intensity varied light emitting diode applications. These studies confirm that the PS is a versatile material with potential for optoelectronics application.

Visible light emission from apnjunction of porous silicon and microcrystalline silicon carbide

1993 ◽  
Vol 63 (9) ◽  
pp. 1209-1210 ◽  
Author(s):  
Toshiro Futagi ◽  
Takahiro Matsumoto ◽  
Masakazu Katsuno ◽  
Yasumitsu Ohta ◽  
Hidenori Mimura ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Porous Silicon ◽  
Visible Light ◽  
Light Emission ◽  
Microcrystalline Silicon ◽  
Visible Light Emission

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

scholarly journals Doping porous silicon with erbium: pores filling as a method to limit the Er-clustering effects and increasing its light emission

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Guido Mula ◽  
Tony Printemps ◽  
Christophe Licitra ◽  
Elisa Sogne ◽  
Francesco D’Acapito ◽  
...  
Keyword(s):  
Porous Silicon ◽  
Light Emission

Optical Properties of Microcrystalline Silicon in Oxide Matrix through Partial Oxidation of Anodized Porous Silicon

1991 ◽  
Vol 256 ◽  
Author(s):  
Toshimichi Ito ◽  
Toshimichi Ohta ◽  
Osamu Arakaki ◽  
Akio Hiraki
Keyword(s):  
Optical Properties ◽  
Porous Silicon ◽  
Partial Oxidation ◽  
Silicon Oxide ◽  
Light Emission ◽  
Wavelength Region ◽  
Microcrystalline Silicon ◽  
Quantum Size ◽  
Visible Luminescence ◽  
Oxide Matrix

ABSTRACTMicrocrystalline silicon embedded in silicon oxide has been prepared by means of partial oxidation of porous silicon produced anodically from degenerate p-Si wafers. Their optical properties such as absorption coefficients and luminescence have been characterized. Results show blue shifts in absorption and photoluminescence spectra in a visible wavelength region with decreasing size of the microcrystalline Si in the Si oxide matrix. The quantum size effect is discussed as well as possible origins of the observed visible luminescence, including light emission from as-anodized (or H-chemisorbed) porous silicon.

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