Effect of the composition of electrolyte on separation of porous silicon film by electrochemical etching

2003 ◽  
Vol 197 (2) ◽  
pp. 507-511 ◽  
Author(s):  
C. S. Solanki ◽  
R. R. Bilyalov ◽  
J. Poortmans ◽  
J.-P. Celis ◽  
J. Nijs
Keyword(s):  
Porous Silicon ◽  
Electrochemical Etching ◽  
Silicon Film ◽  
Effect Of The Composition

The Microstructure and Characteristics of Luminescent Porous Silicon Film Prepared by the Physicochemical

2010 ◽  
Vol 29-32 ◽  
pp. 566-570
Author(s):  
Xiao Jun Wan ◽  
Hui Xia Jin
Keyword(s):  
Porous Silicon ◽  
Chemical Treatment ◽  
Electrochemical Etching ◽  
Silicon Film ◽  
Ultrasonic Waves ◽  
Silicon Films ◽  
Chemical Effect ◽  
Etching Solution ◽  
Hydrogen Bubbles ◽  
Effective Technology

The special physicochemical environment caused by sonic-vacating provides an important outlet for the preparation of highly efficient luminescent porous silicon films. Experimental results show that sonic—chemical treatment is an effective technology for the improvement of the microstructure of porous silicon, and the luminescent efficiency and stability thereof. Luminescent porous silicon films, prepared by ultrasonic—enhanced anode electrochemical etching, display better qualities than the samples prepared by conventional methods widely used at present. This ultrasonic—chemical effect roots in sonic—vacating, i.e. the generation, formation and rapid collapse of bubbles in the etching solution. In the process of the porous silicon being etched, the escape rate and caving-in of hydrogen bubbles in the pores is increased as a result of the work of the ultrasonic waves, which is helpful to the vertical etching of the pores.

Optically Encoded Smart Dust from DBR Porous Silicon

2006 ◽  
Vol 321-323 ◽  
pp. 53-56 ◽  
Author(s):  
Bong Ju Lee ◽  
Sung Gi Kim ◽  
Hong Lae Sohn
Keyword(s):  
Porous Silicon ◽  
Chemical Sensor ◽  
Electrochemical Etching ◽  
Silicon Film ◽  
Bragg Reflector ◽  
Organic Solution ◽  
Scanning Electron Micrograph ◽  
Distributed Bragg Reflector ◽  
Organic Vapors ◽  
Smart Dust

Distributed Bragg reflector (DBR) porous silicons exhibiting unique reflectivity were successfully obtained by an electrochemical etching of silicon wafer using square wave currents. Optically encoded smart dust which retained optical reflectivity was obtained from DBR porous silicon film in organic solution by using ultra-sono method. The size of optically encoded smart dust was measured by field emission scanning electron micrograph (FESEM) and was about 500 nm to few microns depending on the duration of sonication. Investigation for the optical characteristics of smart dust revealed that smart dust could be useful for application such as chemical sensor for detecting organic vapors.

Quantum Confinement Effects on the Dielectric Constant of Porous Silicon

1992 ◽  
Vol 283 ◽  
Author(s):  
R. Tsu ◽  
L. Ioriatti ◽  
J. F. Harvey ◽  
H. Shen ◽  
R. A. Lux
Keyword(s):  
Dielectric Constant ◽  
Porous Silicon ◽  
Size Effects ◽  
Quantum Confinement ◽  
Electrochemical Etching ◽  
Index Of Refraction ◽  
Quantum Size Effects ◽  
Quantum Size ◽  
Quantum Confinement Effects ◽  
Shallow Impurities

ABSTRACTThe reduction of the dielectric constant due to quantum confinement is studied both experimentally and theoretically. Angle resolved ellipsometry measurements with Ar- and He-Ne-lasers give values for the index of refraction far below what can be accounted for from porosity alone. A modified Penn model to include quantum size effects has been used to calculate the reduction in the static dielectric constant (ε) with extreme confinement. Since the binding energy of shallow impurities depends inversely on ε2, the drastic decrease in the carrier concentration as a result of the decrease in ε leads to a self-limiting process for the electrochemical etching of porous silicon.

Nanostructured porous silicon by laser assisted electrochemical etching

2009 ◽  
Vol 285 (3) ◽  
pp. 137-142 ◽  
Author(s):  
J. Li ◽  
C. Lu ◽  
X.K. Hu ◽  
Xiujuan Yang ◽  
A.V. Loboda ◽  
...  
Keyword(s):  
Porous Silicon ◽  
Electrochemical Etching

scholarly journals Porous Silicon Biosensor for the Detection of Bacteria through Their Lysate

Biosensors ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 27
Author(s):  
Roselien Vercauteren ◽  
Audrey Leprince ◽  
Jacques Mahillon ◽  
Laurent A. Francis
Keyword(s):  
Porous Silicon ◽  
Electrochemical Etching ◽  
Bacterial Lysate ◽  
Fast Detection ◽  
Porous Layers ◽  
Deep Blue ◽  
Diffusion Limited ◽  
Colony Forming Units ◽  
Selective Lysis ◽  
Microfabrication Techniques

Porous silicon (PSi) has been widely used as a biosensor in recent years due to its large surface area and its optical properties. Most PSi biosensors consist in close-ended porous layers, and, because of the diffusion-limited infiltration of the analyte, they lack sensitivity and speed of response. In order to overcome these shortcomings, PSi membranes (PSiMs) have been fabricated using electrochemical etching and standard microfabrication techniques. In this work, PSiMs have been used for the optical detection of Bacillus cereus lysate. Before detection, the bacteria are selectively lysed by PlyB221, an endolysin encoded by the bacteriophage Deep-Blue targeting B. cereus. The detection relies on the infiltration of bacterial lysate inside the membrane, which induces a shift of the effective optical thickness. The biosensor was able to detect a B. cereus bacterial lysate, with an initial bacteria concentration of 105 colony forming units per mL (CFU/mL), in only 1 h. This proof-of-concept also illustrates the specificity of the lysis before detection. Not only does this detection platform enable the fast detection of bacteria, but the same technique can be extended to other bacteria using selective lysis, as demonstrated by the detection of Staphylococcus epidermidis, selectively lysed by lysostaphin.

scholarly journals Structural Studies of Zno Nanostructures on Porous Silicon: Effect of Post-Annealing Temperature

2018 ◽  
Vol 7 (3.11) ◽  
pp. 48
Author(s):  
Kevin Alvin Eswar ◽  
Mohd Husairi Fadzillah Suhaimi ◽  
Muliyadi Guliling ◽  
Zuraida Khusaimi ◽  
Mohamad Rusop ◽  
...  
Keyword(s):  
Porous Silicon ◽  
Annealing Temperature ◽  
Electrochemical Etching ◽  
Texture Coefficient ◽  
Zno Nanostructures ◽  
Structural Studies ◽  
X Ray Diffraction ◽  
X Ray ◽  
Post Annealing ◽  
Post Annealing Temperature

ZnO Nanostructures have been successfully deposited on of Porous silicon (PSi) via wet colloid chemical approach. PSi was prepared by electrochemical etching method. ZnO/PSi thin films were annealed in different temperature in the range of 300 °C to 700 °C. Surface morphology studies were conducted using field emission scanning microscopy (FESEM). Flower-like structures of ZnO were clearly seen at annealing temperature of 500 °C. The X-ray diffraction spectra (XRD) have been used to investigate the structural properties. There are three dominant peaks referred to plane (100), (002) and (101) indicates that ZnO has a polycrystalline hexagonal wurtzite structures. Plane (002) shows the highest intensities at annealing temperature of 500 °C. Based on plane (002) analysis, the sizes were in range of 30.78 nm to 55.18. In addition, it was found that the texture coefficient of plane (002) is stable compared to plane (100) and (101). 

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.

Magnetic Properties of Ferrous Ferric Oxide Confined in Porous Silicon

2010 ◽  
Vol 663-665 ◽  
pp. 1142-1145
Author(s):  
Yuan Ming Huang ◽  
Bao Gai Zhai ◽  
Qing Lan Ma ◽  
Ming Meng
Keyword(s):  
Electron Microscopy ◽  
Magnetic Properties ◽  
Iron Oxide ◽  
Porous Silicon ◽  
Ferrous Iron ◽  
Silicon Film ◽  
X Ray ◽  
Loop Measurement ◽  
Scanning Electron

During the chemical synthesis nanometer-sized particles of ferrous iron oxide were in situ infiltrated into the mesopores in a porous silicon film. The microstructures of porous silicon and the magnetic properties of the nanometer-sized particles of the ferrous iron oxide were characterized with scanning electron microscopy, X-ray diffractometry, and the hysteresis loop measurement, respectively. Our results have demonstrated that the magnetic properties of the nanometer-sized Fe3O4 particles can be dramatically modified when they are confined into the mesopores of the porous silicon film.

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