Elaboration of Porous Silicon Multilayer Using Resistive p-Type Si

Porous silicon is largely studied in the field of photonics because of its interesting optical properties. In this work we present an experimental study about the elaboration of a multilayer structure by photoelectrochemical etching. p-Si(100) with resistivity of 100 Ωcm is used in this work. Two different current densities were used namely 150 mA/cm2 and 10 mA/cm2. We found that the anodization time is a crucial parameter for the formation of multilayer structures. The times of 2 and 5 seconds appears as optimal times for the elaboration of multilayer structures with 16 layers. Finally, we have determined that these structures exhibit strong luminescence at 600 nm.

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Self- and Dopant Diffusion in Extrinsic Boron Doped Isotopically Controlled Silicon Multilayer Structures

MRS Proceedings ◽

10.1557/proc-719-f13.11 ◽

2002 ◽

Vol 719 ◽

Cited By ~ 9

Author(s):

Ian D. Sharp ◽

Hartmut A. Bracht ◽

Hughes H. Silvestri ◽

Samuel P. Nicols ◽

Jeffrey W. Beeman ◽

...

Keyword(s):

Multilayer Structure ◽

Secondary Ion Mass Spectrometry ◽

Diffusion Processes ◽

Quantitative Description ◽

Multilayer Structures ◽

Dopant Diffusion ◽

Enhanced Diffusion ◽

Self Diffusion ◽

Boron Doped ◽

P Type

AbstractIsotopically controlled silicon multilayer structures were used to measure the enhancement of self- and dopant diffusion in extrinsic boron doped silicon. 30Si was used as a tracer through a multilayer structure of alternating natural Si and enriched 28Si layers. Low energy, high resolution secondary ion mass spectrometry (SIMS) allowed for simultaneous measurement of self- and dopant diffusion profiles of samples annealed at temperatures between 850°C and 1100°C. A specially designed ion-implanted amorphous Si surface layer was used as a dopant source to suppress excess defects in the multilayer structure, thereby eliminating transient enhanced diffusion (TED) behavior. Self- and dopant diffusion coefficients, diffusion mechanisms, and native defect charge states were determined from computer-aided modeling, based on differential equations describing the diffusion processes. We present a quantitative description of B diffusion enhanced self-diffusion in silicon and conclude that the diffusion of both B and Si is mainly mediated by neutral and singly positively charged self-interstitials under p-type doping. No significant contribution of vacancies to either B or Si diffusion is observed.

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Electroluminescence and Photoluminescence Properties of Porous Silicon Nanostructures with Optimum Current Density of Photo-Electrochemical Anodisation

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.667.180 ◽

2013 ◽

Vol 667 ◽

pp. 180-185

Author(s):

M. Ain Zubaidah ◽

F.S. Husairi ◽

S.F.M. Yusop ◽

Noor Asli Asnida ◽

Mohamad Rusop ◽

...

Keyword(s):

Porous Silicon ◽

Volume Ratio ◽

Boron Doping ◽

Peak Position ◽

Silicon Nanostructures ◽

Etching Time ◽

Photoluminescence Properties ◽

Current Densities ◽

Pl Spectrum ◽

P Type

P-type silicon wafer ( orientation; boron doping; 0.75 ~ 10 Ω cm-1) was used to prepare samples of porous silicon nanostructures (PSiNs). All samples have been prepared by using photo-electrochemical anodisation. A fixed etching time of 30 minutes and volume ratio of electrolyte, hydrofluoric acid 48% (HF48%) and absolute ethanol (C2H5OH), 1:1 were used for various current densities, J. There were sample A (J=10 mA/cm2), sample B (J=20 mA/cm2), sample C (J=30 mA/cm2), sample D (J=40 mA/cm2) and sample E (J=50 mA/cm2). Photoluminescence (PL) and electroluminescence (EL) spectra were investigated. Maximum peak position of PL spectrum at about ~675 nm, while the maximum EL spectrum at about ~650 nm (which is similar to the PL spectrum).

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Porous Silicon Morphology: Photo-Electrochemically Etched by Different Laser Wavelengths

Journal of Nanotechnology in Engineering and Medicine ◽

10.1115/1.4030768 ◽

2015 ◽

Vol 6 (1) ◽

Cited By ~ 1

Author(s):

Shereen M. Faraj ◽

Shaimaa M. Abd Al-Baqi ◽

Nasreen R. Jber ◽

Johnny Fisher

Keyword(s):

Porous Silicon ◽

Electrochemical Etching ◽

Diode Lasers ◽

Focus Of Attention ◽

Blue Laser ◽

Uniform Structure ◽

Porous Layers ◽

Current Densities ◽

P Type ◽

532 Nm

Porous silicon (PS) has become the focus of attention in upgrading silicon for optoelectronics. In this work, various structures were produced depending on the formation parameters by photo-electrochemical etching (PECE) process of n- and p-type silicon wafer at different time durations (5–90 mins) and different current densities (5, 15, and 20 mA/cm2) for each set of time durations. Diode lasers of 405 nm, 473 nm, and 532 nm wavelengths, each 50 mW power, were used to illuminate the surface of the samples during the etching process. The results showed that controlled porous layers were achieved by using blue laser, giving uniform structure which can make it possible to dispense with expensive methods of patterning the silicon.

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Elaboration and Light Emission Properties of Low Doped p-Type Porous Silicon Microcavities

MRS Proceedings ◽

10.1557/proc-452-711 ◽

1996 ◽

Vol 452 ◽

Cited By ~ 11

Author(s):

G. Lérondel ◽

P. Ferrand ◽

R. Romestain

Keyword(s):

Porous Silicon ◽

Near Infrared ◽

Light Emission ◽

Narrow Band ◽

Bragg Reflectors ◽

Strong Emission ◽

Luminescence Efficiency ◽

Fabry Perot ◽

Current Densities ◽

P Type

AbstractWe account for the elaboration of Bragg reflectors and microcavities based on efficiently luminescent porous silicon. A characterisation of very thin porous silicon layers obtained with current densities of formation varying from 1.5 mA to 300 mA is presented. The resulting refractive index variation (typically from 1.37 to 1.86 at 700 nm) enables the elaboration of high quality Bragg reflectors and Fabry-Perot filters from the yellow to the near infrared. Although low doped p-type porous silicon develops rougher interfaces than highly doped p-type porous silicon, its better luminescence efficiency has enabled us to elaborate microcavities with a strong emission in a narrow band.

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Photoluminescent Photonic Devices from Nanostructured Porous Silicon Fabricated Using Lightly Doped Silicon

Journal of Nano Research ◽

10.4028/www.scientific.net/jnanor.4.11 ◽

2009 ◽

Vol 4 ◽

pp. 11-17

Author(s):

O. Sarracino Martínez ◽

J. Escorcia-Garcia ◽

J.M. Gracia-Jiménez ◽

V. Agarwal

Keyword(s):

Optical Properties ◽

Porous Silicon ◽

Duty Cycle ◽

Crystalline Silicon ◽

Photonic Devices ◽

Applied Current ◽

Low Frequencies ◽

Current Densities ◽

P Type ◽

Rugate Filter

In this work, we report the fabrication of porous silicon multilayers using lightly doped, p-type, silicon wafers (resistivity: 14-22 Ω-cm) by pulsed anodic etching. The optical properties have been found to be strongly dependent on the duty-cycle and frequency of the applied current. Less than 50 % of duty-cycle, at low frequencies, is found to show very rough porous silicon – crystalline silicon (PS-cSi) interface. Use of duty cycle above 50 %, in a certain range of frequencies, is found to make the interface smooth. The optical properties of the photonic devices are investigated for 50 % and 75 % of duty-cycle, for different frequencies in the range of 0-1000 Hz, using the current densities of 10, 90 and 150 mA/cm2. The possibility of fabricating rugate filter with this resistivity is also explored.

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The Growth of Porous Layer on Resistive P-Type Silicon in HF/Ethylene Glycol under Illumination

Materials Science Forum ◽

10.4028/www.scientific.net/msf.480-481.217 ◽

2005 ◽

Vol 480-481 ◽

pp. 217-224 ◽

Cited By ~ 1

Author(s):

N. Chiboub ◽

F. Bellal ◽

N. Gabouze ◽

S. Sam

Keyword(s):

Ethylene Glycol ◽

High Frequency ◽

Pore Diameter ◽

Characteristic Size ◽

High Resistivity ◽

Photoelectrochemical Etching ◽

Impedance Measurements ◽

X Ray ◽

Anodization Time ◽

P Type

In the present work, a photoelectrochemical etching method had been performed on resistive p-type Si (100) to eliminate the instability attributed to the high resistivity of substrate comparing to that of electrolyte. The anodization of p-type Si with resistivity ranging from 10 Ωcm to 30 kΩcm was done in HF/ethylene glycol. The resistivity of electrolyte was experimentally determinated by high frequency impedance measurements. As anodization proceeds structures of increasing characteristic size are formed then a steady state is reached, where macropore grow parallel. It shows that pore diameter increases with increasing HF concentration. Whereas, under laser He-Ne irradiation both of nanopores and macropores are observed during the anodization. The nanoporous layer showed to be varying with the light intensity and the anodization time. The proprieties of the porous silicon were investigated by scanning electron microscopy (SEM), Fourier transform infrared (FTIR) and energy-dispersive X-ray (EDX).

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Optimization Of Porous Silicon Reflectance For Solar Cell Applications

MRS Proceedings ◽

10.1557/proc-426-557 ◽

1996 ◽

Vol 426 ◽

Cited By ~ 6

Author(s):

A. X. Coles ◽

R. A. Gerhardt ◽

A. Rohatgi

Keyword(s):

Porous Silicon ◽

Antireflective Coating ◽

Porous Si ◽

Time Intervals ◽

Surface Conditions ◽

Anodization Time ◽

Float Zone ◽

Current Densities ◽

Potential Use ◽

Over Time

AbstractThe potential use of porous silicon as an antireflective coating on solar cells has recently been recognized. This study investigates the effect of current density, anodization time, and surface conditions on the reflectance of porous silicon which was fabricated by anodizing (100) float zone single crystal Si wafers. The wafers were coated on one side with Al prior to anodization, and a HFbased solution was used as the electrolyte. Current densities of 5 – 100 mA/cm2 were used to anodize both polished and unpolished wafers over time intervals ranging from 2sec - 30 minutes. Reflectance properties were tested over the 400 - 1100 nm range, and minimum reflectances of 3 – 5% were achieved. The reflectance of the best porous Si sample normalized with respect to the sun's spectrum compares favorably with the reflectance of a double layer ZnS/ MgF2 with prior texturing.

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Demonstration of the Formation of Porous Silicon Films with Superior Properties Formed on Polished (100) Si with Screen-Printed Back Contacts

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.31.249 ◽

2007 ◽

Vol 31 ◽

pp. 249-253 ◽

Cited By ~ 1

Author(s):

Priyanka Singh ◽

Shailesh N. Sharma ◽

G. Bhagavannarayana ◽

M. Husain ◽

M. Lal

Keyword(s):

Porous Silicon ◽

Gravimetric Analysis ◽

Back Contact ◽

X Ray Diffraction ◽

Crystalline Perfection ◽

X Ray ◽

Anodization Time ◽

Current Densities ◽

Scanning Electron ◽

Screen Printed

Porous silicon (PS) layers were formed by anodization on polished substrates of (1 0 0) Si at different current densities for a fixed anodization time of 30 mins. using different screenprinted/ evaporated back contacts (Ag, Al) respectively. The PS films has been characterized by high resolution X-ray diffraction (HRXRD), photoluminescence (PL), Scanning Electron Microscopy (SEM) and Fourier Transform Infrared (FTIR) techniques respectively. Porosity and thickness of PS layers were estimated by gravimetric analysis. The properties of PS formed using screen-printed Ag & Al as the back contacts (SP-(Ag/Al)) was found to be superior as compared to the corresponding films with evaporated back contacts (EV-(Ag/Al)). The PS formed with screenprinted Ag & Al-back contacts shows better crystalline perfection, higher stability, higher PL efficiency and negligible PL decay compared to that formed with evaporated Ag & Al- as the back contact for the same current density and time of anodization.

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