scholarly journals Boron Induced Crystallization of Silicon Oon Glass: An Alternate Way to Crystallize Amorphous Silicon Films for Solar Cells

2021 ◽  
Author(s):  
SUCHETA JUNEJA ◽  
sushil kumar
Keyword(s):  
Solar Cells ◽  
Amorphous Silicon ◽  
Film Structure ◽  
Silicon Films ◽  
Window Layer ◽  
Hydrogenated Silicon ◽  
Boron Doped ◽  
Absorption Studies ◽  
Crystallite Sizes ◽  
Film Characteristics

Abstract Demand for efficient window layer in thin film solar cells with high crystallinity is ever increasing that finds important application in multi-junction/tandem silicon solar cells. Doping of diborane (B2H6) in hydrogenated silicon films using plasma discharge decomposition of silane (SiH4) and (B2H6) gases were analyzed. The boron flow (FB) to silane ratio was varied from 0–0.30. Variation in film characteristics with B2H6 gas-phase ratio were analyzed, and concluded that doping boron induces crystallization in hydrogenated amorphous silicon (a-Si: H) film structure. The Raman and field emission scanning electron spectroscopy (FESEM) confirmed the boron induced crystallinity effect in silicon films at different diborane flow. The results showed that as boron content increases beyond certain ratio, silicon crystallization suppresses and the crystallite sizes were also reduced. From results, it was observed that crystallinity in FB = 0.05 is 79 % and decreases to 77 % when films are slightly higher doped (FB = 0.10) and further decreases when the films were heavily doped. These results validate that boron suppresses silicon crystallization due to local deformations caused by the impurities. Infra-red absorption studies and their analysis also confirm the crystallization in boron doped films with additional band appears at ~ 611 cm− 1. This band is named as boron induced crystallinity mode of vibrational spectra. The estimated hydrogen content (CH) decreases confirmed crystallinity in the silicon structure with boron doping. Further, the energy dispersive spectroscopy (EDX) indicates the presence of boron and other impurities in deposited silicon films. The effect of boron on crystallinity and crystallite size as well as the mechanism were presented in detailed.

Improvement of Single-Junction a-Si:H Thin-Film Solar Cells Toward 10% Efficiency

2011 ◽  
Vol 1321 ◽  
Author(s):  
P. H. Cheng ◽  
S. W. Liang ◽  
Y. P. Lin ◽  
H. J. Hsu ◽  
C. H. Hsu ◽  
...  
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Amorphous Silicon ◽  
Chemical Vapor ◽  
Thin Film Solar Cells ◽  
Window Layer ◽  
Electron Hole ◽  
Single Junction ◽  
Boron Doped ◽  
Hydrogenated Amorphous

ABSTRACTThe hydrogenated amorphous silicon (a-Si:H) single-junction thin-film solar cells were fabricated on SnO2:F-coated glasses by plasma-enhanced chemical vapor deposition (PECVD) system. The boron-doped amorphous silicon carbide (a-SiC:H) was served as the window layer (p-layer) and the undoped a-SiC:H was used as a buffer layer (b-layer). The optimization of the p/b/i/n thin-films in a-Si:H solar cells have been carried out and discussed. Considering the effects of light absorption, electron-hole extraction and light-induced degradation, the thicknesses of p, b, n and i layers have been optimized. The optimal a-Si:H thin-film solar cell having an efficiency of 9.46% was achieved, with VOC=906 mV, JSC=14.42 mA/cm2 and FF=72.36%.

Boron doped amorphous diamond window layer deposited by filtered arc for amorphous silicon alloy p–i–n solar cells

2009 ◽  
Vol 93 (9) ◽  
pp. 1652-1656 ◽  
Author(s):  
Jiaqi Zhu ◽  
Huijie Zhao ◽  
Chunzhu Jiang ◽  
Jiecai Han ◽  
Manlin Tan ◽  
...  
Keyword(s):  
Solar Cells ◽  
Amorphous Silicon ◽  
Window Layer ◽  
Silicon Alloy ◽  
Boron Doped

An Exploratory Survey of p-Layers for a-Si:H Solar Cells

1994 ◽  
Vol 336 ◽  
Author(s):  
Y.-M. Li ◽  
F. Jackson ◽  
L. Yang ◽  
B.F. Fieselmann ◽  
L. Russell
Keyword(s):  
Solar Cells ◽  
Amorphous Silicon ◽  
Conversion Efficiency ◽  
Good Alternative ◽  
Window Layer ◽  
Coated Glass ◽  
Glass Substrates ◽  
Boron Doped ◽  
Exploratory Survey ◽  
Wide Gap

ABSTRACTThe window layer (p-layer) critically affects the conversion efficiency of a-Si:H based p-i-n type solar cells. This paper surveys possible alternative window materials in comparison with the standard boron doped a-SiC:H p-layer. A novel wide-gap amorphous silicon alloy, a-Si:F:H, will be shown to be a good alternative p-layer. As an example of nontraditional p-layer, boron based alloys (e.g., a-B:H) exhibit notable photovoltaic action in a-Si:H solar cells. We comment on attempts to deposit μc-Si alloy window layers on textured TCO-coated glass substrates.

Oxygen modified diamond-like carbon as window layer for amorphous silicon solar cells

Solar Energy ◽  
2012 ◽  
Vol 86 (1) ◽  
pp. 220-230 ◽  
Author(s):  
Neeraj Dwivedi ◽  
Sushil Kumar ◽  
Sukhbir Singh ◽  
Hitendra K. Malik
Keyword(s):  
Solar Cells ◽  
Amorphous Silicon ◽  
Window Layer ◽  
Silicon Solar Cells ◽  
Diamond Like Carbon

scholarly journals Silicon Heterojunction Solar Cells with p-Type Silicon Carbon Window Layer

Crystals ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 402 ◽  
Author(s):  
Chia-Hsun Hsu ◽  
Xiao-Ying Zhang ◽  
Ming Jie Zhao ◽  
Hai-Jun Lin ◽  
Wen-Zhang Zhu ◽  
...  
Keyword(s):  
Solar Cells ◽  
Amorphous Silicon ◽  
Band Gap ◽  
Flow Rate ◽  
Computer Aided Design ◽  
Hydrogenated Amorphous Silicon ◽  
Wavelength Region ◽  
Window Layer ◽  
Solar Cell Performance ◽  
Hydrogenated Amorphous

Boron-doped hydrogenated amorphous silicon carbide (a-SiC:H) thin films are deposited using high frequency 27.12 MHz plasma enhanced chemical vapor deposition system as a window layer of silicon heterojunction (SHJ) solar cells. The CH4 gas flow rate is varied to deposit various a-SiC:H films, and the optical and electrical properties are investigated. The experimental results show that at the CH4 flow rate of 40 sccm the a-SiC:H has a high band gap of 2.1 eV and reduced absorption coefficients in the whole wavelength region, but the electrical conductivity deteriorates. The technology computer aided design simulation for SHJ devices reveal the band discontinuity at i/p interface when the a-SiC:H films are used. For fabricated SHJ solar cell performance, the highest conversion efficiency of 22.14%, which is 0.33% abs higher than that of conventional hydrogenated amorphous silicon window layer, can be obtained when the intermediate band gap (2 eV) a-SiC:H window layer is used.

DEVELOPMENT OF HIGHLY CONDUCTIVE BORON-DOPED MICROCRYSTALLINE SILICON FILMS FOR APPLICATION IN SOLAR CELLS

2006 ◽  
Vol 20 (03) ◽  
pp. 303-314 ◽  
Author(s):  
QING-SONG LEI ◽  
ZHI-MENG WU ◽  
JIAN-PING XI ◽  
XIN-HUA GENG ◽  
YING ZHAO ◽  
...  
Keyword(s):  
Solar Cells ◽  
Substrate Temperature ◽  
Chemical Vapor ◽  
Dark Conductivity ◽  
Silicon Films ◽  
Microcrystalline Silicon ◽  
Very High Frequency ◽  
Boron Doped ◽  
Deposition Processes ◽  
P Type

We have examined the deposition of highly conductive boron-doped microcrystalline silicon (μc- Si:H ) films for application in solar cells. Depositions were conducted in a very high frequency plasma enhanced chemical vapor deposition (VHF PECVD) chamber. In the deposition processes, various substrate temperatures (TS) were applied. Highly conductive p-type microcrystalline silicon films were obtained at substrate temperature lower than 210°C. The factors that affect the conductivity of the films were investigated. Results suggest that the dark conductivity, which was determined by the Hall mobility and carrier concentration, is influenced by the structure. The properties of the films are strongly dependent on the substrate temperature. With TS increasing, the dark conductivity (σd) increases initially; reach the maximum values at certain TS and then decrease. Also, we applied the boron-doped μc- Si:H as p-layers to the solar cells. An efficiency of about 8.5% for a solar cell with μc- Si:H p-layer was obtained.

Growth of Thin μc-Si:H on Intrinsic a-Si:H for Solar Cells Application

1996 ◽  
Vol 452 ◽  
Author(s):  
P. Pemet ◽  
M. Goetz ◽  
H. Keppner ◽  
A. Shah
Keyword(s):  
Stainless Steel ◽  
Solar Cells ◽  
Solar Cell ◽  
High Efficiency ◽  
Solar Cell Performance ◽  
Hydrogenated Silicon ◽  
Boron Doped ◽  
High Efficiency Solar Cells ◽  
Amorphous Substrates ◽  
Interface Treatment

AbstractThe <p> μc-SiC:H / <i> a-Si:H junction can be considered to be a sub-system of a n/i/p solar cell. Optimised performance of this junction can be assumed to be a key feature for obtaining high efficiency solar cells.In this paper the authors present results on the conductivity of boron doped microcrystalline hydrogenated silicon (<p> μc-Si:H) thin films deposited on amorphous substrates (e.g. glass or glass/<i> a-Si:H). It is shown that, without any treatment of the substrate or of the underlying surface, the <p> layers showed a strongly reduced conductivity. This indicates either a bad nucleation or a poor microcrystalline behaviour. By using an appropriate surface treatment of the substrate, a gain in photoconductivity of about three orders of magnitude could be obtained (σ > 3 S/cm at a layer thickness of 400Å). We conclude from this, that for thin <p> type μc-Si:H layers the nucleation conditions are essential for obtaining best electric properties of the film w.r.t. solar cell performance.Based on these results, interface treatment was successfully implemented in n/i/p solar cells deposited on TCO coated glass and stainless steel. The results of these experiments are also presented.

Low Temperature Crystallization of Amorphous Silicon Films Using an Excimer Laser

1989 ◽  
Vol 149 ◽  
Author(s):  
S. E. Ready ◽  
J. B. Boyce ◽  
R. Z. Bachrach ◽  
R. I. Johnson ◽  
K. Winer ◽  
...  
Keyword(s):  
Amorphous Silicon ◽  
Excimer Laser ◽  
Laser Energy ◽  
Amorphous Material ◽  
Surface Region ◽  
Silicon Films ◽  
Starting Material ◽  
Near Surface ◽  
Silicon Thin Films ◽  
Crystallite Sizes

ABSTRACTIn an effort to enhance the electrical properties of silicon thin films, we have performed recrystallization experiments on a variety of amorphous silicon films using an excimer laser. The intense, pulsed UV produced by the laser (308nm, using XeCl gas) is highly absorbed by the amorphous material and thus provides intense localized heating in the near surface region. Two types of starting films were studied: plasma CVD a-Si:H and LPCVD a-Si. The subsequent modification produces crystallites whose structure and electrical characteristics vary due to starting material and laser scan parameters. The treated films have been characterized using Raman, x-ray diffraction, TEM, SIMS and transport measurements. The results indicate that crystallites nucleate in the surface region. The degree of crystallization near the surface increases dramatically as a function of deposited laser energy density and less so as a function of laser shot density. The hall mobility of the highly crystallized samples exhibit an increase of 2 orders of magnitude over the amorphous starting material. In the PECVD material, the rapid diffusion of hydrogen causes voids to be formed at intermediate laser energy densities and removal of film at higher energy densities. The LPCVD material withstands the high laser energies to produce well crystallized films with crystallite sizes greater then 1000Å.

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