Structural, Morphological, Chemical and Optical Properties of Porous Silicon Prepared By Electrochemical Etching (original) (raw)
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In this paper, the nanocrystalline porous silicon (PS) films are prepared by electrochemical etching of p-type silicon wafer with current density (7 mA/cm2) and etching times on the formation nano-sized pore array with a dimension of around different etching time. The films were characterized by the measurement of XRD, FTIR spectroscopy and atomic force microscopy properties (AFM). We have estimated crystallites size from X-Ray diffraction about nanoscale for porous silicon and Atomic Force microscopy confirms the nanometric size Chemical fictionalization during the electrochemical etching show on the surface chemical composition of PS. The etching possesses inhomogeneous microstructures that contain a -Si clusters (Si3–Si–H) dispersed in amorphous silica matrix . From the FTIR analyses showed that the Si dangling bonds of the as-prepared PS layer have large amount of Hydrogen to form weak Si–H bonds. The atomic force microscopy investigation shows the rough silicon surface, with increasing etching process (current density and etching time) porous structure nucleates which leads to an increase in the depth and width (diameter) of surface pits. Consequently, the surface roughness also increase.
Morphological and Structural Properties of Porous Silicon (PSi)
International Letters of Chemistry, Physics and Astronomy
This study includes the effect of the etching time on the morphology of the surfaces produced using the electrochemical method of silicon ( p-type), where it was found that the etching leads to increase the porosity layer of silicon. The production of nanocrystalline structures and control of their production conditions is the first step to control the properties of the devices. These are very important applications for the etching of renewable energy.
2010
Porous silicon (PS) is defined as a composition of a silicon skeleton permeated by a network of pores or in other word, PS is a network of silicon nanowires and nanoholes which are formed when the crystalline silicon wafers are etched electrochemically in electrolyte solution such as hydrofluoric (HF) acid . PS shows different features in comparison to the bulk silicon such as shifting of fundamental absorption edge into the short wavelength and photoluminescence visible region. The PS material possesses interesting characteristics such as larger surface to volume ratio, high-intensity of nano porous structure and low refractive index. This paper presents the synthesis and characterization of electrochemically anodized PS structures. The effect of short anodization time on the PS structures is investigated. The PS surface morphology and optical properties are characterized using scanning electron microscopy (SEM) and photoluminescence (PL) spectrometer, respectively.
Morphological and Optical Properties of Porous Silicon
Engineering and Technology Journal
In this work photo-electrochemical etching was used to synthesize uniform and non-uniform macro porous silicon from n-type with orientation (100). Specimens were anodized in a sol of 25% HF: C2H2OH at 1:1 rate. Morphology and porosity of the samples were studied. Optical characteristics (reflection and photoluminescence) of PS samples by changing current density (10, 12, 14 and 16 mA/cm 2) for fixed etching time (8min) and power density (17mW/cm 2) by using red laser illumination wavelength (645nm) were investigated. Porous silicon samples imaged via scanning electron microscope (SEM), which showed the topography of silicon surface and pores distribution.
Porous silicon (PS) has been fabricated by Photo-electrochemical etching. Porous silicon was anodized on n-type Si in light using a current density of 20mA/cm2 for 10 min. The porous structure formation was confirmed using XRD and AFM studies. The root mean square (RMS) roughness of the Porous silicon layer is found to be around 47.5 nm and the ten point height was 317 nm. The average of pores diameter was 419.98nm, and the grain growth is columnar with a (211) preferred orientation. The grain size of the PS was estimated from the Scherer’s formula and found to be 73 nm. All the properties of the porous silicon layer, such as porosity and the thickness depend on the anodization parameters. The porosity (P) was approximately 77 %. The thickness of the layer formed during an anodization in constant current was 3.54nm in gravimetric method, while its value was 1.77nm by using the theoretical relation.
Nanostructure and optical propertes of porous silicon layer
Maǧallaẗ ǧāmiʻaẗ kirkūk, 2015
In this paper nanostructures Porous silicon layers have been prepared by electrochemical etching (ECE) technique of (111) P-type silicon wafer with a solution Electrolytic HF: ethanol at a concentration of 1:2 with various anodization currents and etching time of 20 min. The morphological, structural and optical properties of nanostructure porous silicon were investigated by Atomic Force Microscopy (AFM), X-Ray Diffraction (XRD) and Photoluminescence (PL) respectively. From AFM images, we found that the PS layer has sponge like structure, and average diameter of pore and thickness of PS layer increased with increasing of the anodization currents. X-ray diffraction show that the crystal size was reduced toward nanometric scale, and then a broadening of diffraction peaks (111) was observed. The band gap of the samples was measured through the photoluminescence (PL) peak.
Study of the Electrical Properties of Porous Silicon Prepared by Electrochemical Etching Technique
Journal of Southwest Jiaotong University, 2019
In our work, a P-type porous silicon (PSi) with orientation (100) have been prepared using the chemical etching method; the goal is to study the electrical properties of PSi samples prepared with completely different etching current (7, 9, 11 and 13) mA and glued for (15 min) anodization time. Depending on the atomic force microscopy (AFM) investigation, we notice the roughness of Si surface increases with increasing etching current because of increases within the dimension (diameter) of surface pits. The electrical and optoelectronic properties of prepared PSi, specifically capacitance-voltage (C-V), current-voltage (I-V), responsivity and detectivity, are analyzed. It had been found that electrical characteristics of porous Si samples measured in dark (Id) and below illumination (IPh) will be fitted well by the equations of thermal emission. From this point of view, Schottky barrier height (ɸB) and ideality factor (n) of made-up photodetectors were calculated. We tended to determi...
Fabrication and Characterization of Porous Silicon
World Scientific News, 2018
In this work, nanocrystalline porous silicon layers were fabricated by photoelectrochemical etching of n type silicon (n-Si) wafer. Different etching time (15, 20, 25 and 30) min and 10 mA/cm 2 current density were tested to study their effect on the formation nanosized pore array. Porous silicon is investigation by X-Ray diffractions (XRD) and atomic force microscopy properties (AFM). Crystallites size was estimated by X-Ray diffraction. Atomic Force microscopy confirmed the nonmetric size Chemical Anodization the electrochemical etching was noticed of PS. The atomic force microscopy investigation showed the rough silicon surface which increased with etching time porous structure nucleates which leads to an increase in the depth and width (diameter) of surface pits.
Journal of Molecular Structure
Silicon-on insulator (SO1) wafers, consisting of 33 micron thick p-type silicon epitaxial layer grown on 280 micron thick n-type (111) silicon substrate, were electrochemically etched in hydrofluoric acid (HF) to produce porous silicon (PS) samples. The pores of different size and different depth were obtained by etching at different time duration, from 10 to 80 min, using the constant concentration of 48% HF in ethanol solution. The structural and optical properties of porous layers were investigated by Raman, FTIR and photoluminescence (PL) spectroscopy, and scanning electron microscopy. SEM images showed high density of micrometer-sized pores whose morphology and density depended on the etching duration. For all samples the observed PL peak is in the visible spectral range. The intensity of the PL peak was increased with the etching zime. the exception was the epitaxial layer of the sampled etched for 80 min. It showed the strong decrease in the PL peak intensity. For thiw sample...