scholarly journals The effect of current density on the structures and photoluminescence of n-type porous silicon

2019 ◽  
Vol 15 (34) ◽  
pp. 15-28
Author(s):  
Isam M. Ibrahim
Keyword(s):  
Porous Silicon ◽  
Band Gap ◽  
Current Density ◽  
Electrochemical Etching ◽  
Silicon Layer ◽  
Porous Silicon Layer ◽  
Etching Time ◽  
Etching Technique ◽  
Force Microscopy ◽  
Homogeneous Pattern

Porous silicon (PS) layers were formed on n-type silicon (Si) wafers using Photo- electrochemical Etching technique (PEC) was used to produce porous silicon for n-type with orientation of (111). The effects of current density were investigated at: (10, 20, 30, 40, and50) mA/cm2 with etching time: 10min. X-ray diffraction studies showed distinct variations between the fresh silicon surface and the synthesized porous silicon. The maximum crystal size of Porous Silicon is (33.9nm) and minimum is (2.6nm) The Atomic force microscopy (AFM) analysis and Field Emission Scanning Electron Microscope (FESEM) were used to study the morphology of porous silicon layer. AFM results showed that root mean square (RMS) of roughness and the grain size of porous silicon decreased as etching current density increased and FESEM showed that a homogeneous pattern and confirms the formation of uniform porous silicon. The chemical bonding and structure were investigated by using Fourier transformation infrared spectroscopy (FTIR). The band gap of the samples obtained from photoluminescence (PL). These results showed that the band gap of porous silicon increase with increasing porosity.

scholarly journals The Effect of Etching Time On Structural Properties of Porous Quaternary AlInGaN Thin Films

2021 ◽  
Vol 19 (50) ◽  
pp. 77-83
Author(s):  
Ghasaq Ali Tomaa ◽  
Alaa Jabbar Ghazai
Keyword(s):  
Porous Silicon ◽  
Crystal Size ◽  
Electrochemical Etching ◽  
Silicon Layer ◽  
Porous Silicon Layer ◽  
Etching Time ◽  
Etching Technique ◽  
Force Microscopy ◽  
Atomic Force ◽  
Homogeneous Pattern

Using photo electrochemical etching technique (PEC), porous silicon (PS) layers were produced on n-type silicon (Si) wafers to generate porous silicon for n-type with an orientation of (111) The results of etching time were investigated at: (5,10,15 min). X-ray diffraction experiments revealed differences between the surface of the sample sheet and the synthesized porous silicon. The largest crystal size is (30 nm) and the lowest crystal size is (28.6 nm) The analysis of Atomic Force Microscopy (AFM) and Field Emission Scanning Electron Microscope (FESEM) were used to research the morphology of porous silicon layer. As etching time increased, AFM findings showed that root mean square (RMS) of roughness and porous silicon grain size decreased and FESEM showed a homogeneous pattern and verified the formation of uniform porous silicon.

I-V and Surface Topography Study of Nanostructure Porous Silicon Layer Prepared by Electrochemical Etching

2012 ◽  
Vol 576 ◽  
pp. 519-522 ◽  
Author(s):  
Fadzilah Suhaimi Husairi ◽  
Maslihan Ain Zubaidah ◽  
Shamsul Faez M. Yusop ◽  
Rusop Mahmood Mohamad ◽  
Saifolah Abdullah
Keyword(s):  
Electrical Properties ◽  
Porous Silicon ◽  
Surface Topography ◽  
Electrochemical Etching ◽  
Silicon Layer ◽  
Porous Silicon Layer ◽  
Force Microscopy ◽  
Atomic Force ◽  
Current Voltage ◽  
P Type

This article reports on the electrical properties of porous silicon nanostructures (PSiNs) in term of its surface topography. In this study, the PsiNs samples were prepared by using different current density during the electrochemical etching of p-type silicon wafer. PSiNs has been investigated its electrical properties and resistances for different surface topography of PSiNs via current-voltage (I-V) measurement system (Keithley 2400) while its physical structural properties was investigated by using atomic force microscopy (AFM-XE100).

Effects of Electrochemical Etching Time on the Performance of Porous Silicon Solar Cells on Crystalline n-Type (100) and (111)

2017 ◽  
Vol 46 ◽  
pp. 45-56 ◽  
Author(s):  
Khalid Omar ◽  
Khaldun A. Salman
Keyword(s):  
Solar Cells ◽  
Porous Silicon ◽  
Crystalline Silicon ◽  
Electrochemical Etching ◽  
Silicon Layer ◽  
Porous Silicon Layer ◽  
Silicon Solar Cells ◽  
Etching Time ◽  
Crystalline Silicon Solar Cells ◽  
Coating Layers

Electrochemical etching was carried out to produce porous silicon based on crystalline silicon n-type (100) and (111) wafers. Etching times of 10, 20, and 30 min were applied. Porous silicon layer was used as anti-reflection coating on crystalline silicon solar cells. The optimal etching time is 20 min for preparing porous silicon layers based on crystalline silicon n-type (100) and (111) wafers. Nanopores with high porosity were produced on the porous silicon layer based on crystalline silicon n-type (100) and (111) wafers with average diameters of 5.7 and 5.8 nm, respectively. Average crystallite sizes for the porous silicon layer based on crystalline silicon n-type (100) and (111) wafers were 20.57 and 17.45 nm at 20 and 30 min, respectively, due to the increase in broadening of the full width at half maximum. Photoluminescence peaks for porous silicon layers based on crystalline silicon n-type (100) and (111) wafers increased with growing porosity and a great blue shift in luminescence. The minimum effective coefficient of reflection was obtained from porous silicon layers based on the crystalline silicon n-type (100) wafer compared with n-type (111) wafer and as-grown at different etching times. Porous silicon layers based on the crystalline silicon n-type (100) wafer at 20 min etching time exhibited excellent light trapping at wavelengths ranging from 400 to 1000 nm. Thus, fabricated crystalline silicon solar cells based on porous silicon (100) anti-reflection coating layers achieved the highest efficiency at 15.50% compared to porous silicon (111) anti-reflection coating layers. The efficiency is characterized applying I-V characterization system under 100 mW/cm2 illumination conditions.

Effect of Etching Time on Electrical and Optical Properties of Porous Silicon

2013 ◽  
Vol 667 ◽  
pp. 397-401
Author(s):  
S.F.M. Yusop ◽  
N. Azaman ◽  
Hartini Ahmad Rafaie ◽  
S. Amizam ◽  
Saifollah Abdullah ◽  
...  
Keyword(s):  
Optical Properties ◽  
Porous Silicon ◽  
Electrochemical Etching ◽  
Silicon Layer ◽  
Porous Silicon Layer ◽  
Constant Current ◽  
Voltage Source ◽  
Etching Time ◽  
Constant Current Density ◽  
Wafer Substrate

The characterized on porous silicon layer by using photoluminescence (PL) and I-V measurement (I-V) has been done. Porous silicon was formed by electrochemical etching on (100) p-type Si wafer substrate with the constant current density (20mA/cm2) and variable the etching time. The samples ware prepared under various etching time and properties of porous silicon depend on an etching time. Porous silicon has been used in humidity sensors to detect humidity through changes of its electrical properties. The samples of porous silicon were characterized by using Photoluminescence Spectroscopy (PL) that used to characterize optical properties while I-V Measurement (I-V) used to characterize porous silicon junction properties using a linear voltage source. The result shows PL intensity is increase while the wavelength is decrease for etching time of PSi is longer. For the I-V measurement result shows the etching time affect the resistance of sample due to its porosity.

scholarly journals Modification of Surface Properties of Silicon Wafers by Laser-Assisted Electrochemical Etching

2018 ◽  
Vol 80 ◽  
pp. 30-39
Author(s):  
Hasan A Hadi
Keyword(s):  
Porous Silicon ◽  
Optical Microscopy ◽  
Surface Topography ◽  
Electrochemical Etching ◽  
Silicon Layer ◽  
Porous Silicon Layer ◽  
Diffraction Peak ◽  
Etching Time ◽  
Layer Formation ◽  
Xrd Patterns

In this paper, the structural properties of porous silicon layer PSL were reported. Photo-assisted (laser) electrochemical etching PECE technique used to fabrication PSL from n-type wafer silicon as a function of etching time. Optical microscopy OM image is confirmed that the surface topography of porous silicon layer formation was a mud-like structure. The porosity and thickness have been determined gravimetrically are varied from 61% to 82% and 7.2 µm to 9.4µm respectively. The XRD patterns show that one diffraction peak for all PSL through anodization duration and it is assigned to the (400) plane and data confirmed the porous silicon PS was nanocrystalline.

Impact of Changing Anodization Current Density on Structural and Morphological Properties of PSi Layer

2015 ◽  
Vol 53 ◽  
pp. 180-192
Author(s):  
Wasna'a M. Abdulridha ◽  
Raheem G. Kadhim ◽  
Raid A. Ismail
Keyword(s):  
Current Density ◽  
Electrochemical Etching ◽  
Silicon Layer ◽  
Average Diameter ◽  
Peak Position ◽  
Porous Silicon Layer ◽  
Morphological Properties ◽  
Etching Time ◽  
X Ray ◽  
P Type

In this paper, porous silicon layer prepared by electrochemical etching process of (100) p-type silicon wafer at different current densities (9, 11, 14 and 16)mA/cm² for 15min etching time. The structural and morphological properties were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM),energy dispersive X-ray (EDX), atomic force microscopy (AFM), fourier transformation infrared spectroscopy (FTIR) and photoluminescence (PL). XRD investigation exhibited that all the layers were monocrystalline structure with preferred orientation (211). AFM investigation indicates that PSi layer sponge like structure, and average diameter of pore increased with increasing current density, our result showed a PSi structure with porosity of (34.19-75.36%). From FTIR analysis, it has been show that the Si dangling bonds of the prepared PSi layer have large amount of Hydrogen to form (Si-H) bond. Increasing the current density from (9-16mA/cm²)leads to shift the photoluminescence peak position from (1.63-1.66eV).

STUDY OF POROUS SILICON SURFACE PROPERTIES

1996 ◽  
Vol 03 (02) ◽  
pp. 1235-1239
Author(s):  
K. W. CHEAH ◽  
T. Y. LEUNG ◽  
M. H. CHAN ◽  
S. K. SO
Keyword(s):  
Porous Silicon ◽  
Surface States ◽  
Silicon Layer ◽  
Structural Difference ◽  
Porous Silicon Layer ◽  
Etching Time ◽  
Free Standing ◽  
Force Microscopy ◽  
Photothermal Deflection Spectroscopy ◽  
Atomic Force

Porous silicon is a material with a coral-like structure which has a fractal surface. To study these aspects of porous silicon and its relationship with the luminescence property, we have used atomic force microscopy (AFM). Samples were prepared using either pure HF or HF diluted with ethanol. From the results of AFM, distinct structural difference was observed from samples prepared by these two etchants. If we relate the structures to their respective photoluminescence spectra, it appears that finer structure produced shorter wavelength peak photoluminescence. However, the columns of the samples were too large for one to attribute the luminescence to quantum confinement only. Hence, an alternative model may be required to explain the luminescence mechanism. We have also observed that the composition of the etchant can also affect the evolution of the fractal dimension with respect to etching time. Probing of the surfcace electron states was performed using photothermal deflection spectroscopy (PDS). In order to ensure that only porous silicon layer was probed, free-standing films of various porosity were produced for the PDS measurement. The probe energy range was from 0.56 eV to 2.5 eV so that both the bulk states and the surface states were probed. The results showed that there is a clear blueshift of the energy band gap with respect to porosity, and the absorption coefficient decreases with porosity increase at a fixed photon energy. Overtones of hydrides and fluorides of silicon were also observed.

scholarly journals Effect of photo chemical etching and electro chemical etching on the topography of porous silicon wafers surfaces

2019 ◽  
Vol 24 (4) ◽  
pp. 52
Author(s):  
Amjad Hussein Jassem
Keyword(s):  
Porous Silicon ◽  
Layer Thickness ◽  
Porous Layer ◽  
Chemical Etching ◽  
Chemical Method ◽  
Pore Diameter ◽  
Electrochemical Etching ◽  
Silicon Layer ◽  
Porous Silicon Layer ◽  
Etching Time

In This research we study the effect of photo chemical etching and electrochemical etching on topography of porous silicon surfaces, the results showed that photo chemical etching produced roughness silicon layer which can have thickness be less of porous silicon layer which is produced by electro chemical etching When all the wafers have same etching time  and hydrofluoric solution (HF) concentration, the wafers have same resistance (10 Ω.cm). Also the results showed the roughness of porous silicon layers produced  by  electro chemical method which is bigger than the roughness of porous silicon layers produced by photo chemical method and the results of roughness of porous silicon layers, Pore diameter and porous layer thickness were produced by electro chemical method (1.55(µm) ((0.99(µm)) and ((1.21(µm) respectively), the results of roughness of porous silicon layers, Pore diameter and porous layer thickness were produced by photo chemical method 0.63)) nm -1.55)) (µm) ),so the (84.9 (nm)- and (3.94(nm) respectively . This is reinforces because of using the electro chemical to etching the wafer surf ace of bulk silicon and changing it to roughness silicon surface  be share in success of many practicalities.   http://dx.doi.org/10.25130/tjps.24.2019.072

scholarly journals Effect of SnS Thin Film on the Performance of Porous Silicon Photodiode

2016 ◽  
Vol 63 ◽  
pp. 67-76 ◽  
Author(s):  
Ahmed N. Abd ◽  
Wasna'a M. Abdulridha ◽  
Mohammed Odda Dawood
Keyword(s):  
Thin Film ◽  
Porous Silicon ◽  
Silicon Layer ◽  
Porous Silicon Layer ◽  
Etching Time ◽  
X Ray Diffraction ◽  
Silicon Photodiode ◽  
Force Microscopy ◽  
Atomic Force ◽  
Evaporation Technique

In this study, Al/SnS/PS/n-Si/Al photodiode was fabricated and investigated. SnS thin film were prepared by thermal evaporation technique on porous silicon layer which prepared by anodization technique at 32mA/cm2 etching current density and etching time 15min.The characteristics of porous silicon and SnS were investigated by using x-ray diffraction XRD, atomic force microscopy AFM, Fourier transformation infrared spectroscopy FT-IR.Dark and illuminated current-voltage I-V characteristics, spectral responsivity, specific detectivity of photodiode were investigated after depositing. Significant improvement in photosensitivity and detectivity of porous silicon photodiode after SnS deposition on porous silicon was noticed.

scholarly journals Porous silicon prepared by photo electrochemical etching assisted by laser

2019 ◽  
Vol 15 (32) ◽  
pp. 122-129
Author(s):  
Falah A-H Mutlak
Keyword(s):  
Porous Silicon ◽  
Current Density ◽  
Crystalline Silicon ◽  
Electrochemical Etching ◽  
Silicon Layer ◽  
Porous Silicon Layer ◽  
Maximum Diameter ◽  
Face Centered Cubic ◽  
The Face ◽  
Face Centered

Porous silicon (PS) layers are prepared by anodization fordifferent etching current densities. The samples are thencharacterized the nanocrystalline porous silicon layer by X-RayDiffraction (XRD), Atomic Force Microscopy (AFM), FourierTransform Infrared (FTIR). PS layers were formed on n-type Siwafer. Anodized electrically with a 20, 30, 40, 50 and 60 mA/cm2current density for fixed 10 min etching times. XRD confirms theformation of porous silicon, the crystal size is reduced towardnanometric scale of the face centered cubic structure, and peakbecomes a broader with increasing the current density. The AFMinvestigation shows the sponge like structure of PS at the lowercurrent density porous begin to form on the crystalline silicon, whenthe current density increases, pores with maximum diameter areformed as observed all over the surface. FTIR spectroscopy shows ahigh density of silicon bonds, it is very sensitive to the surroundingambient air, and it is possible to oxidation spontaneously.

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