Optimization Of Porous Silicon Reflectance For Solar Cell Applications

1996 ◽  
Vol 426 ◽  
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.

Porous Silicon as a Sacrificial Material for Micromachining of Silicon Optical Platforms

1997 ◽  
Vol 486 ◽  
Author(s):  
M. Guendouz ◽  
P. Joubert ◽  
N. Pedrono ◽  
J. Le Rouzic
Keyword(s):  
Porous Silicon ◽  
Chemical Etching ◽  
Sacrificial Layer ◽  
Porous Si ◽  
Fiber Alignment ◽  
Patterned Substrate ◽  
Anodization Time ◽  
Experimental Parameters ◽  
Heavily Doped ◽  
Optical Fiber Alignment

AbstractPorous silicon obtained by the anodization of heavily doped n+-type silicon wafers was used as a sacrificial layer to micromachine silicon platforms. The effect of experimental parameters, such as the nature of the masking layer, current density and anodization time, on the geometry of the porous Si formed in patterned substrate is shown. Advantages of this method on the orientation-dependent chemical etching (ODCE), which is classically used for optical fiber alignment, are discussed.

Microstructure of Porous Silicon Thin Films

1998 ◽  
Vol 4 (S2) ◽  
pp. 632-633
Author(s):  
Y. Berta ◽  
R. A. Gerhardt
Keyword(s):  
Solar Cells ◽  
Porous Silicon ◽  
Current Density ◽  
Electrochemical Anodization ◽  
Antireflective Coating ◽  
Silicon Thin Films ◽  
Potential Applications ◽  
Current Densities ◽  
Low Efficiency ◽  
The Cost

Porous silicon has potential applications in the microelectronics industry. It has been investigated as an electroluminescent source1, as a sensing device in chemical sensors and as an antireflective coating for solar cells. The low efficiency of the solar cells is enhanced by the antireflective coating that porous silicon provides, while the cost of fabrication of the cells is decreased. Porous silicon is normally processed by electrochemical anodization of silicon wafers. Since parameters such as current density, anodization time, and surface conditions can affect the microstructure of the films obtained, we varied the current density to study the effect of the microstructure on the resultant reflectance for the purpose of improving it. It has been found that higher current densities result in higher reflectance films than the lower current densities.

Elaboration of Porous Silicon Multilayer Using Resistive p-Type Si

2009 ◽  
Vol 609 ◽  
pp. 201-205
Author(s):  
O. Fellahi ◽  
T. Hadjersi ◽  
L. Guerbous
Keyword(s):  
Porous Silicon ◽  
Multilayer Structure ◽  
Multilayer Structures ◽  
Photoelectrochemical Etching ◽  
Anodization Time ◽  
Strong Luminescence ◽  
Current Densities ◽  
The Times ◽  
P Type ◽  
Crucial Parameter

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.

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

2007 ◽  
Vol 31 ◽  
pp. 249-253 ◽  
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.

Enhancement of efficiency in graphene/porous silicon solar cells by co-doping graphene with gold nanoparticles and bis(trifluoromethanesulfonyl)-amide

2017 ◽  
Vol 5 (35) ◽  
pp. 9005-9011 ◽  
Author(s):  
Ju Hwan Kim ◽  
Dong Hee Shin ◽  
Ha Seung Lee ◽  
Chan Wook Jang ◽  
Jong Min Kim ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Solar Cells ◽  
Porous Silicon ◽  
Au Nanoparticles ◽  
Silicon Solar Cells ◽  
Porous Si ◽  
Co Doping ◽  
Si Solar Cells ◽  
First Time

The co-doping of graphene with Au nanoparticles and bis(trifluoromethanesulfonyl)-amide is employed for the first time to enhance the performance of graphene/porous Si solar cells.

Optical Studies of porous Silicon

1993 ◽  
Vol 298 ◽  
Author(s):  
T. Lin ◽  
M. E. Sixta ◽  
J. N. Cox ◽  
M. E. Delaney
Keyword(s):  
Optical Properties ◽  
Fourier Transform ◽  
Steady State ◽  
Porous Silicon ◽  
Ftir Spectroscopy ◽  
Optical Studies ◽  
Etched Silicon ◽  
Bending Modes ◽  
P Type ◽  
Over Time

AbstractThe optical properties of both electrochemically anodized and chemically stain-etched porous silicon are presented. Fourier transform infrared (FTIR) spectroscopy showed that absorbance in stain-etched samples was 3x and 1.7x greater than in anodized samples for the SiH/SiH2 stretch and scissors-bending modes, respectively. Also, oxygen is detected in stain-etched samples immediately after formation, unlike anodized samples. Photoluminescence measurements showed different steady state characteristics. Electrochemical-etched silicon samples stored in air increased in photoluminescent intensity over time, unlike the stain-etched samples. A photoluminescent device made by anodization on epitaxial p-type material (0.4 Ωm) on n-type substrate (0.1 Ω-cm) did not exhibit electroluminescence.

scholarly journals Hubungan Perilaku Perdagangan Investor Dengan Volume Perdagangan Di Bursa Efek Indonesia

2009 ◽  
Vol 2 (1) ◽  
Author(s):  
Ghazali Syamni
Keyword(s):  
Trading Volume ◽  
Stock Exchange ◽  
Time Interval ◽  
Time Intervals ◽  
Using Data ◽  
Changes Over Time ◽  
Relationship Of ◽  
The Relationship ◽  
Order Pattern ◽  
Over Time

This paper examines the relationship of behavior trading investor using data detailed transaction history-corporate edition demand and order history in Indonesia Stock Exchange during period of March, April and May 2005. Peculiarly, behavior placing of investor order at trading volume. The result of this paper indicates that trading volume order pattern to have pattern U shape. The pattern happened that investors have strong desires to places order at the opening and close of compared to in trading periods. While the largest orders are of market at the opening indicates that investor is more conservatively when opening, where many orders when opening has not happened transaction to match. In placing order both of investor does similar strategy. By definition, informed investors’ orders more large than uninformed investors. If comparison of order examined hence both investors behavior relatively changes over time. But, statistically shows there is not ratio significant. This implies behavior trading of informed investors and uninformed investors stable relative over time. The result from regression analysis indicates that informed investors to correlate at trading volume in all time intervals, but not all uninformed investors correlates in every time interval. This imply investor order inform is more can explain trading volume pattern compared to uninformed investor order in Indonesia Stock Exchange. Finally, result of regression also finds that order status match has greater role determines trading volume pattern intraday especially informed buy match and informed sale match. While amend, open and withdraw unable to have role to determine intraday trading volume pattern.

Visible Electro- and Photoluminescence from Porous Silicon and its Related Optoelectronic Properties

1991 ◽  
Vol 256 ◽  
Author(s):  
Nobuyoshi Koshida ◽  
Hideki Koyama
Keyword(s):  
Porous Silicon ◽  
Optical Absorption ◽  
Size Effect ◽  
Band Gap ◽  
Visible Region ◽  
Optoelectronic Properties ◽  
Porous Si ◽  
Quantum Size ◽  
Effect Model ◽  
Injection Type

ABSTRACTThe optoelectronic properties of porous Si (PS) are presented in terms of electroluminescence (EL), photoluminescence (PL), photoconduction (PC), and optical absorption. Observations of injection-type EL, efficient PL, band-gap widening, and photosensitivities In the visible region are consistent with the quantum size effect model in PS.

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

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).

Sign in / Sign up

Export Citation Format

Share Document