Field-Assisted Germanium Induced Crystallization of Amorphous Silicon

2003 ◽  
Vol 762 ◽  
Author(s):  
J. Derakhshandeh ◽  
S. Mohajerzadeh ◽  
N. Golshani ◽  
E. Asl Soleimani ◽  
M.D. Robertson
Keyword(s):  
Electric Field ◽  
Amorphous Silicon ◽  
Applied Voltage ◽  
Crucial Role ◽  
Silicon Films ◽  
Electric Voltage ◽  
External Voltage ◽  
Annealing Conditions ◽  
Induced Crystallization

AbstractA field-assisted germanium-induced crystallization of amorphous silicon on glass is reported at temperatures below 500°C. Silicon films with a thickness of 0.1um are covered with 500Å of germanium as the seed of crystallization. Applying an electric field enhances the growth from both cathode and anode sides. XRD, SEM and TEM analyses have been used to study the crystallinity of the samples which have been treated under different annealing conditions, all confirming the polycrystalline nature of the annealed silicon films. The value of the applied voltage plays a crucial role in the crystalline quality of Si layers. While samples treated without an external voltage are not polycrystalline, an electric voltage of 10 V applied for a 1cm separation between anode and cathode, seems suitable for achieving good poly-crystalline Si layers. The size of grains varies between 0.1 and 0.2μm, as observed using SEM.

Crystallization of Tin-Implanted Amorphous Silicon Thin Films

1992 ◽  
Vol 279 ◽  
Author(s):  
Fuyu Lin ◽  
Miltiadis K. Hatalis
Keyword(s):  
Amorphous Silicon ◽  
Crystallization Process ◽  
Silicon Films ◽  
Grain Structure ◽  
Crystallization Time ◽  
Silicon Thin Films ◽  
Fine Grain ◽  
Annealing Conditions ◽  
Transmission Electron ◽  
Si Films

ABSTRACTThe crystallization of Sn-implanted amorphous silicon was studied as a function of tin implant dose and annealing conditions by transmission electron microscopy. The films were implanted at an energy of 110 keV with a dose in the range of 5 × 1014 to 5×1016 cm−2 and were annealed at a temperature in the range of 450°C to 550°C. An enhanced rate of crystallization in amorphous Si-Sn films compared to the non-implanted amorphous silicon films during thermal annealing was observed. The crystallization process of Si films implanted with tin at a dose of 2.5×1016 cm−2 or less is very similar to unimplanted silicon films except higher nucleation rates and shorter crystallization time were observed with increasing tin dose. Films implanted with tin at a dose of 2.5×1016 cm−2 or more display extremely rapid crystallization (3 hours at 450°C) and very fine grain structure (10 nm); no substantial grain growth has been observed during lurther annealing, but some single crystal-like areas were formed. In-situ annealing of silicon implanted to 5×1016 cm−2 showed that the crystallization process is enhanced by the formation of the liquid tin phase.

Hydrophobic Surfaces Prepared by Aluminum-Induced Crystallization of Amorphous Silicon

2007 ◽  
Author(s):  
Ying Song ◽  
Rahul Premachandran Nair ◽  
Min Zou
Keyword(s):  
Amorphous Silicon ◽  
Annealing Temperature ◽  
Textured Surfaces ◽  
Surface Wetting ◽  
Water Contact ◽  
Annealing Conditions ◽  
Wetting Property ◽  
Percentage Area ◽  
Induced Crystallization ◽  
Aluminum Induced Crystallization

This paper reports fabrication and understanding of hydrophobic silicon nano-textured surfaces produced by aluminum-induced crystallization (AIC) of amorphous silicon (a-Si). In this study, the effects of annealing temperature and duration on surface topography and wetting property were investigated. The results showed that surface wetting property directly correlates with the percentage area coverage by the nano-textures, which in turn was determined by the annealing conditions. The largest water contact angle (WCA) obtained from this research is 137°.

Polysilicon Films Formed On Alumina By Aluminium Induced Crystallization Of Amorphous Silicon

2006 ◽  
Vol 910 ◽  
Author(s):  
Etienne Pihan ◽  
Abdelilah Slaoui ◽  
Claude Maurice
Keyword(s):  
Amorphous Silicon ◽  
Grain Orientation ◽  
Coincident Site Lattice ◽  
Grain Structure ◽  
Structural Quality ◽  
Orientation Imaging ◽  
Polysilicon Films ◽  
Si Films ◽  
Induced Crystallization

AbstractWe investigated the structural quality of polysilicon films fabricated by the aluminium induced crystallization (AIC) of amorphous silicon on alumina substrates. We analyzed the overall crystallographic quality of the poly-Si films in terms of grain size distribution and grain orientation versus crystallization temperature. For these studies, we used extensively the orientation imaging micrograph (OIM) technique, a very powerful tool that allows elucidating the inner-grain structure, the grain boundaries, the grain orientation. From our analysis, we may conclude that the polysilicon films formed by AIC on alumina substrates have the following features: (i) for all investigated temperatures, most of the silicon grains have a deviation angle from (100) crystallographic orientation between 5 and 25°; (ii) increasing the annealing temperature tends to decrease the (100) preferred orientation; (iii) the angular boundary distribution revealed that the main defects are those that have been observed inside isolated dentrites, namely low angle boundaries (<2°) and coincident site lattice boundaries such as Σ3, Σ9 and Σ27.

Excimer Laser Crystallized Amorphous Silicon Films: Effects of Shot Density and Substrate Temperature

1991 ◽  
Vol 219 ◽  
Author(s):  
R. I. Johnson ◽  
G. B. Anderson ◽  
S. E. Ready ◽  
J. B. Boyce
Keyword(s):  
Energy Density ◽  
Substrate Temperature ◽  
Amorphous Silicon ◽  
Laser Energy ◽  
Silicon Films ◽  
Laser Energy Density ◽  
Laser Crystallization ◽  
Average Grain Size ◽  
Substrate Temperatures

ABSTRACTLaser crystallization of a-Si thin films has been shown to produce materials with enhanced electrical properties and devices that are faster and capable of carrying higher currents. The quality of these polycrystalline films depends on a number of parameters such as laser energy density, shot density, substrate temperature, and the quality of the starting material. We find that the average grain size and transport properties of laser crystallized amorphous silicon films increase substantially with laser energy density, increase only slightly with laser shot density, and are unaffected by substrate temperatures of up to 400°C. The best films are those processed in vacuum but films of fair quality can also be obtained in air and nitrogen atmospheres.

Spatially localized current-induced crystallization of amorphous silicon films

2008 ◽  
Vol 354 (19-25) ◽  
pp. 2305-2309 ◽  
Author(s):  
B. Rezek ◽  
E. Šípek ◽  
M. Ledinský ◽  
P. Krejza ◽  
J. Stuchlík ◽  
...  
Keyword(s):  
Amorphous Silicon ◽  
Silicon Films ◽  
Induced Crystallization

Laser Induced Crystallization of Amorphous Silicon Films on Glass for Thin Film Solar Cells

1998 ◽  
Vol 166 (2) ◽  
pp. 629-634 ◽  
Author(s):  
G. Andrä ◽  
J. Bergmann ◽  
F. Falk ◽  
E. Ose ◽  
H. Stafast
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Amorphous Silicon ◽  
Silicon Films ◽  
Thin Film Solar Cells ◽  
Induced Crystallization

Simulation of Quantum Efficiency Spectroscopy for Amorphous Silicon P-I-N Junctions

1999 ◽  
Vol 557 ◽  
Author(s):  
Rodney Estwick ◽  
Vikram L. Dalal
Keyword(s):  
Electric Field ◽  
Amorphous Silicon ◽  
Quantum Efficiency ◽  
Applied Voltage ◽  
Forward Bias ◽  
Hole Mobility ◽  
Limited Range ◽  
D Model ◽  
Defect Densities ◽  
Minority Carriers

AbstractQuantum efficiency(QE) spectroscopy of amorphous silicon and alloy solar cells has been used for many years now to determine the mobility-lifetime products for minority carriers. Similarly, matching of I(V) curves, assuming a linear model for collection as a function of applied voltage, has been used to quantify the effects of degradation on cell performance by estimating changes in the collection length [or range] of holes. In this paper, we do a numerical simulation of these techniques, using the AMPS I-D model developed by Fonash and his coworkers. The simulation shows that neither the lifetime nor the electric field in the devices is constant as a function of position. Nor is the electric field a linear function of applied voltage, particularly when the voltage exceeds about half the built-in voltage. The uniformity of the lifetime depends on the applied bias and on the defect densities in the material. This variation in electric field and lifetime and nonlinearity with applied voltage makes questionable some of the conclusions drawn from fitting device I(V) curves, particularly under forward bias. However, when one uses only a limited range of forward bias, or, preferably, make measurements in cells with thicker i layers under reverse bias, one c.an make reasonable estimates of the hole mobility-lifetime(μτ) product or the collection lengthl The simulations also show that indeed, it is the hole μτ product which is the limiting parameter.

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