Effect of etching time on characterizations of porous silicon passivated by a nano-silver layer

Achieving efficient visible photoluminescence from porous-silicon (PSi) is demanding for optoelectronic and solar cells applications. Improving the absorption and emission features of PSi is challenging. Photo-electro-chemical etching assisted formation of PSi layers on n-type (111) silicon (Si) wafers is reported. Samples are prepared at constant current density (~30 mA/cm2) under varying etching times of 10, 15, 20, 25, and 30 min. The influence of etching time duration on the growth morphology and spectral properties are inspected. Room temperature photoluminescence (PL) measurement is performed to determine the optical properties of as-synthesized samples. Sample morphologies are imaged via Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM). The thickness and porosity of the prepared samples are estimated using the gravimetric method. The emission and absorption data is further used to determine the samples band gap and electronic structure properties. Results and analyzed, interpreted with different mechanisms and compared.

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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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Effect of etching time on structure of p-type porous silicon

Applied Surface Science ◽

10.1016/j.apsusc.2018.04.228 ◽

2018 ◽

Vol 461 ◽

pp. 44-47 ◽

Cited By ~ 5

Author(s):

Martin Kopani ◽

Milan Mikula ◽

Daniel Kosnac ◽

Pavol Vojtek ◽

Jan Gregus ◽

...

Keyword(s):

Porous Silicon ◽

Etching Time ◽

P Type

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Effect of current density on the porous silicon preparation as gas sensors**

Journal of the Mechanical Behavior of Materials ◽

10.1515/jmbm-2021-0027 ◽

2021 ◽

Vol 30 (1) ◽

pp. 257-264

Author(s):

Muna H. Kareem ◽

Adi M. Abdul Hussein ◽

Haitham Talib Hussein

Keyword(s):

Porous Silicon ◽

Gas Sensors ◽

Current Density ◽

Room Temperature ◽

Low Cost ◽

High Surface ◽

Volume Ratio ◽

Etching Time ◽

Force Microscopy ◽

Materials Used

Abstract In this study, porous silicon (PSi) was used to manufacture gas sensors for acetone and ethanol. Samples of PSi were successfully prepared by photoelectrochemical etching and applied as an acetone and ethanol gas sensor at room temperature at various current densities J= 12, 24 and 30 mA/cm2 with an etching time of 10 min and hydrofluoric acid concentration of 40%. Well-ordered n-type PSi (100) was carefully studied for its chemical composition, surface structure and bond configuration of the surface via X-ray diffraction, atomic force microscopy, Fourier transform infrared spectroscopy and photoluminescence tests. Results showed that the best sensitivity of PSi was to acetone gas than to ethanol under the same conditions at an etching current density of 30 mA/cm2, reaching about 2.413 at a concentration of 500 parts per million. The PSi layers served as low-cost and high-quality acetone gas sensors. Thus, PSi can be used to replace expensive materials used in gas sensors that function at low temperatures, including room temperature. The material has an exceptionally high surface-to-volume ratio (increasing surface area) and demonstrates ease of fabrication and compatibility with manufacturing processes of silicon microelectronics.

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Influence of Etching Time on Surface Structural Properties of p- and n- Type Porous Silicon Nanostructures by Photo-Electrochemical Anodic Etching

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.576.511 ◽

2012 ◽

Vol 576 ◽

pp. 511-515

Author(s):

N.A. Asli ◽

Maslihan Ain Zubaidah ◽

S.F.M. Yusop ◽

Khairunnadim Ahmad Sekak ◽

Mohammad Rusop ◽

...

Keyword(s):

Porous Silicon ◽

Crystalline Silicon ◽

Surface Characteristic ◽

Electrochemical Anodization ◽

Silicon Nanostructures ◽

Etching Time ◽

Force Microscopy ◽

Etching Parameters ◽

P Type ◽

Substrate Doping

Porous silicon nanostructures (PSiN) are nanoporous materials which consist of uniform network of interconnected pore. The structure of PSiN is depending on etching parameters, including current density, HF electrolyte concentration, substrate doping type and level. In this work, the results of a structural p-type and n-type of porous silicon nanostructures were investigated by Field Emission Scanning Electron Microscopy (FESEM) and Atomic Force Microscopy (AFM) is reported. Samples were prepared by photo-electrochemical anodization of p- and n-type crystalline silicon in HF electrolyte at different etching time. The surface morphology of PSiN was studied by FESEM with same magnification shown n-type surface form crack faster than p-type of PSiN. While the topography and roughness of PSiN was characterize by AFM. From topography shown the different etching time for both type PSiN produce different porosity and roughness respectively. There is good agreement between p- and n-type have different in terms of surface characteristic.

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

ISRN Optics ◽

10.5402/2012/958412 ◽

2012 ◽

Vol 2012 ◽

pp. 1-6 ◽

Cited By ~ 4

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.

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Ferromagnetic Nanostructures Incorporated in Quasi-One-Dimensional Porous Silicon Channels Suitable for Magnetic Sensor Applications

Journal of Nanomaterials ◽

10.1155/jnm/2006/18125 ◽

2006 ◽

Vol 2006 ◽

pp. 1-7 ◽

Cited By ~ 3

Author(s):

P. Granitzer ◽

K. Rumpf ◽

H. Krenn

Keyword(s):

Porous Silicon ◽

Deposition Process ◽

Switching Behavior ◽

Etching Time ◽

Mesoporous Silicon ◽

Sensor Applications ◽

Self Organized ◽

Nanocomposite System ◽

Silicon Structures ◽

Field Sensor

Mesoporous silicon structures are fabricated during an anodization process of highly doped n-type silicon in hydrofluoric acid solution. The resulting pores are oriented perpendicular to the surface and exhibit a diameter of about 50 nm and a length up to 50μm, controlled by the etching time. The growth of the pores is self-organized and depends on the crystal orientation of the used silicon wafer. The achieved channels, highly oriented along the (100) direction, are filled with nickel in a second electrochemical step. The deposition process leads to a distribution between high aspect ratio Ni-wires and Ni-particles of the incorporated metal. This achieved (porous silicon/Ni)-nanocomposite system exhibits a twofold switching behavior of the magnetization curve at two different field ranges. This property gives rise to high-magnetic field sensor applications based on a silicon technology.

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