Metastability of Luminescent Porous Silicon

1992 ◽  
Vol 283 ◽  
Author(s):  
S. Mtyazaki ◽  
K. Sakamoto ◽  
K. Shiba ◽  
M. Hirose
Keyword(s):  
Porous Silicon ◽  
Luminescence Intensity ◽  
Chemical Etching ◽  
Anomalous Temperature Dependence ◽  
Porous Si ◽  
Anomalous Temperature ◽  
Type C ◽  
P Type ◽  
Quenching Phenomenon ◽  
Subsequent Chemical

ABSTRACTPhotoluminescence from l–3μm thick porous Si layers prepared by anodization of p-type c-Si wafers and subsequent chemical etching exhibits an anomalous temperature dependence and light-induced degradation. The luminescence intensity is almost quenched at temperatures below 30K and recovered by laser irradiation at 48K. This quenching phenomenon is not observed for PS thicker than 10μm. The luminescence fatigue is partially recovered by annealing at 150°C for 5min during which no further oxidation takes place. These observations are interpreted in terms of the structural metastability of hydrogen-terminated porous Si.

Photovoltaic and Electroluminescent Properties of Stainetched Porous Silicon Based Heterojunctions

1995 ◽  
Vol 405 ◽  
Author(s):  
D. Dimova-Malinovska ◽  
M. Tzolov ◽  
M. Kamenova ◽  
N. Tzenov ◽  
M. Sendova-Vassileva ◽  
...  
Keyword(s):  
Light Emission ◽  
Photovoltaic Effect ◽  
Luminescent Properties ◽  
Porous Si ◽  
Photoelectric Properties ◽  
Type C ◽  
P Type ◽  
Silicon Based ◽  
Electrical Bias ◽  
Stain Etching

AbstractThe results of photoelectric properties and electroluminescent studies of structures ZnO/porous Si/p-type c-Si/Al and ZnO/porous Si/p-n c-Si junction/Al are presented. Porous Si is prepared by stain etching of c-Si covered with thin Al film. The transparent ZnO film allows light emission through the top surface of the device under forward electrical bias. Photocurrent is observed under reverse bias and a photovoltaic effect is measured on the p-n junction PS device. The model based on injection of minority carriers through a narrow energy barrier into the porous Si and the presence of the barrier at the interface porous Si/c-Si is suggested for describing the electrical, photoelectric and luminescent properties of the structures.

scholarly journals Morphology and FT IR spectra of porous silicon

2017 ◽  
Vol 68 (7) ◽  
pp. 53-57 ◽  
Author(s):  
Martin Kopani ◽  
Milan Mikula ◽  
Daniel Kosnac ◽  
Jan Gregus ◽  
Emil Pincik
Keyword(s):  
Porous Silicon ◽  
Ir Spectra ◽  
Silicon Layer ◽  
Porous Silicon Layer ◽  
Layer Formation ◽  
Porous Si ◽  
Ft Ir ◽  
P Type ◽  
Type Sample ◽  
Ftir Investigation

AbstractThe morphology and chemical bods of p-type and n-type porous Si was compared. The surface of n-type sample is smooth, homogenous without any features. The surface of p-type sample reveals micrometer-sized islands. FTIR investigation reveals various distribution of SiOxHycomplexes in both p-and n-type samples. From the conditions leading to porous silicon layer formation (the presence of holes) we suggest both SiOxHyand SiFxHycomplexes in the layer.

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.

scholarly journals Peculiarities of Photoluminescence in Porous Silicon Prepared by Metal-Assisted Chemical Etching

ISRN Optics ◽  
2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Igor Iatsunskyi ◽  
Valentin Smyntyna ◽  
Nykolai Pavlenko ◽  
Olga Sviridova
Keyword(s):  
Porous Silicon ◽  
Chemical Etching ◽  
Etching Time ◽  
Force Microscopy ◽  
Porous Layers ◽  
Atomic Force ◽  
Silicon Nanostructure ◽  
Metal Assisted Chemical Etching ◽  
Concentrated Solution ◽  
P Type

Photoluminescent (PL) porous layers were formed on p-type silicon by a metal-assisted chemical etching method using H2O2 as an oxidizing agent. Silver particles were deposited on the (100) Si surface prior to immersion in a solution of HF and H2O2. The morphology of the porous silicon (PS) layer formed by this method was investigated by atomic force microscopy (AFM). Depending on the metal-assisted chemical etching conditions, the macro- or microporous structures could be formed. Luminescence from metal-assisted chemically etched layers was measured. It was found that the PL intensity increases with increasing etching time. This behaviour is attributed to increase of the density of the silicon nanostructure. It was found the shift of PL peak to a green region with increasing of deposition time can be attributed to the change in porous morphology. Finally, the PL spectra of samples formed by high concentrated solution of AgNO3 showed two narrow peaks of emission at 520 and 550 nm. These peaks can be attributed to formation of AgF and AgF2 on a silicon surface.

Luminescence Activation of Porous Silicon by Post-Anodization Treatment

1992 ◽  
Vol 283 ◽  
Author(s):  
A. Kux ◽  
F. Muller ◽  
F. Koch
Keyword(s):  
Particle Size ◽  
Chemical Composition ◽  
Porous Silicon ◽  
Depth Distribution ◽  
Electrochemical Etching ◽  
Relative Importance ◽  
Porous Si ◽  
Ambient Conditions ◽  
Photochemical Etching ◽  
P Type

ABSTRACTWe prepare “nonluminescing” porous Si by electrochemical etching (50 mA/cm2 in 50% HF diluted 1:1 with ethanol) of 1 Ω(100) p-type wafers in the absence of light in order to study the subsequent luminescence activation by postprocessing. The treatments are: photochemical etching, ageing under ambient conditions, thermal oxidation. The study reveals remarkable inhomogeneities in the depth distribution of the luminescence and allows us to comment on the relative importance of particle size, spin density and chemical composition for the luminescence.

Porous Silicon as a Sacrificial Material for Micromachining of Silicon Optical Platforms

1997 ◽  
Vol 486 ◽  
Author(s):  
M. Guendouz ◽  
P. Joubert ◽  
N. Pedrono ◽  
J. Le Rouzic
Keyword(s):  
Porous Silicon ◽  
Chemical Etching ◽  
Sacrificial Layer ◽  
Porous Si ◽  
Fiber Alignment ◽  
Patterned Substrate ◽  
Anodization Time ◽  
Experimental Parameters ◽  
Heavily Doped ◽  
Optical Fiber Alignment

AbstractPorous silicon obtained by the anodization of heavily doped n+-type silicon wafers was used as a sacrificial layer to micromachine silicon platforms. The effect of experimental parameters, such as the nature of the masking layer, current density and anodization time, on the geometry of the porous Si formed in patterned substrate is shown. Advantages of this method on the orientation-dependent chemical etching (ODCE), which is classically used for optical fiber alignment, are discussed.

Anomalous temperature dependence of photoluminescence in porous silicon

1993 ◽  
Vol 62 (4) ◽  
pp. 331-333 ◽  
Author(s):  
K. L. Narasimhan ◽  
S. Banerjee ◽  
A. K. Srivastava ◽  
A. Sardesai
Keyword(s):  
Porous Silicon ◽  
Temperature Dependence ◽  
Anomalous Temperature Dependence ◽  
Anomalous Temperature

The Influence of Local Ambient Atmosphere on the Electroluminescent Stability of Porous Silicon Diodes

1994 ◽  
Vol 358 ◽  
Author(s):  
Libing Zhang ◽  
Jeffery L. Coffer ◽  
Bruce E. Gnade ◽  
DaXue Xu ◽  
Russell F. Pinizzotto
Keyword(s):  
Porous Silicon ◽  
Surface Oxidation ◽  
Spectroscopic Studies ◽  
Inert Gases ◽  
Ambient Atmosphere ◽  
Porous Si ◽  
Si Substrates ◽  
Integrated Intensity ◽  
The Stability ◽  
P Type

ABSTRACTIn this work, the influence of surrounding ambient atmosphere on the stability of electroluminescent (EL) porous Si (PS) diodes fabricated from anodic oxidation of epitaxially grown p-type layers on n-type Si substrates is investigated. These structures are characterized using photoluminescence (PL), electroluminescence (EL), and infrared (IR) spectrosopies, as well as scanning electron microscopy (SEM). Such structures yield orange emission with maxima near 620 nm upon the application of moderate applied voltages (3-7 V). In strong oxidizing environments, EL intensity degrades completely within 30 minutes; in contrast, the integrated intensity remains essentially unchanged in the same timeframe in the presence of a vigorous flow of inert gases such as nitrogen and argon. Infrared spectroscopic studies strongly suggest that electroluminescence degradation is related to porous silicon surface oxidation.

scholarly journals Formation and Evaluation of Silicon Substrate with Highly-Doped Porous Si Layers Formed by Metal-Assisted Chemical Etching

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Yijie Li ◽  
Nguyen Van Toan ◽  
Zhuqing Wang ◽  
Khairul Fadzli Bin Samat ◽  
Takahito Ono
Keyword(s):  
Electrical Conductivity ◽  
Seebeck Coefficient ◽  
Contact Resistance ◽  
Power Factor ◽  
Chemical Etching ◽  
Porous Si ◽  
Si Substrate ◽  
Si Substrates ◽  
Output Performance ◽  
Metal Assisted Chemical Etching

AbstractPorous silicon (Si) is a low thermal conductivity material, which has high potential for thermoelectric devices. However, low output performance of porous Si hinders the development of thermoelectric performance due to low electrical conductivity. The large contact resistance from nonlinear contact between porous Si and metal is one reason for the reduction of electrical conductivity. In this paper, p- and n-type porous Si were formed on Si substrate by metal-assisted chemical etching. To decrease contact resistance, p- and n-type spin on dopants are employed to dope an impurity element into p- and n-type porous Si surface, respectively. Compared to the Si substrate with undoped porous samples, ohmic contact can be obtained, and the electrical conductivity of doped p- and n-type porous Si can be improved to 1160 and 1390 S/m, respectively. Compared with the Si substrate, the special contact resistances for the doped p- and n-type porous Si layer decreases to 1.35 and 1.16 mΩ/cm2, respectively, by increasing the carrier concentration. However, the increase of the carrier concentration induces the decline of the Seebeck coefficient for p- and n-type Si substrates with doped porous Si samples to 491 and 480 μV/K, respectively. Power factor is related to the Seebeck coefficient and electrical conductivity of thermoelectric material, which is one vital factor that evaluates its output performance. Therefore, even though the Seebeck coefficient values of Si substrates with doped porous Si samples decrease, the doped porous Si layer can improve the power factor compared to undoped samples due to the enhancement of electrical conductivity, which facilitates its development for thermoelectric application.

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