Large Grained, Low Defect Density Polycrystalline Silicon on Glass Substrates by Large-area Diode Laser Crystallisation

2012 ◽  
Vol 1426 ◽  
pp. 251-256 ◽  
Author(s):  
Bonne Eggleston ◽  
Sergey Varlamov ◽  
Jialiang Huang ◽  
Rhett Evans ◽  
Jonathon Dore ◽  
...  
Keyword(s):  
Diode Laser ◽  
Polycrystalline Silicon ◽  
Crystalline Silicon ◽  
Defect Density ◽  
Open Circuit ◽  
Large Area ◽  
High Quality ◽  
Glass Substrates ◽  
Silicon Thin Films ◽  
Open Circuit Voltages

ABSTRACTA new method to form high quality crystalline silicon thin films on cheap glass substrates is developed using a single pass of a line-focus cw diode laser in air. The laser process results in the formation of large high-quality crystals as they grow laterally in the scan direction – seeded by the previously crystallised region. Grains 10 μm in thickness, up to millimetres in length and hundreds of microns in width have been grown with virtually zero detectable intragrain defects. Another mode is found which results in much smaller crystals grown by partial melting. The dominant grain boundaries identified are Σ3 <111> 60° twins. Hall mobilities as high as 470 cm2/Vs have been recorded. A diffused emitter is used to create a p-n junction at the rear of the films which produces open-circuit voltages as high as 539 mV.

scholarly journals Effect of Halogen on the Structure of Low Temperature Polycrystalline Silicon Thin Films Fabricated on Glass Substrates.

1999 ◽  
Vol 107 (1251) ◽  
pp. 1099-1104 ◽  
Author(s):  
Toshio KAMIYA ◽  
Yoshiteru MAEDA ◽  
Kouichi NAKAHATA ◽  
Takashi KOMARU ◽  
Charles M. FORTMANN ◽  
...  
Keyword(s):  
Thin Films ◽  
Low Temperature ◽  
Polycrystalline Silicon ◽  
Glass Substrates ◽  
Silicon Thin Films

Large Area Flexible Amorphous Silicon Position Sensitive Detectors

2000 ◽  
Vol 609 ◽  
Author(s):  
Elvira M.C. Fortunato ◽  
Donatello Brida ◽  
Isabel M.M. Ferreira ◽  
H. M.B. Åguas ◽  
Patrícia Nunes ◽  
...  
Keyword(s):  
Amorphous Silicon ◽  
Spectral Response ◽  
Chemical Vapour ◽  
Open Circuit ◽  
Large Area ◽  
Force Microscopy ◽  
Glass Substrates ◽  
Chemical Vapour Deposition Technique ◽  
Position Sensitive ◽  
Position Sensitive Detectors

ABSTRACTLarge area thin film position sensitive detectors based on amorphous silicon technology have been prepared on polyimide substrates using the conventional plasma enhanced chemical vapour deposition technique. The sensors have been characterised by spectral response, illuminated I-V characteristics and position detectability measurements. The obtained one dimensional position sensors with 5 mm wide and 60 mm long present a maximum spectral response at 600 nm, an open circuit voltage of 0.6 V and a position detectability with a correlation of 0.9989 associated to a standard deviation of 1×10−2, comparable to those ones produced on glass substrates. The surface of the sensors at each stage of fabrication was investigated by Atomic Force Microscopy.

scholarly journals Characterization of Defects and Stress in Polycrystalline Silicon Thin Films on Glass Substrates by Raman Microscopy

2011 ◽  
Vol 2011 ◽  
pp. 1-14 ◽  
Author(s):  
Kuninori Kitahara ◽  
Toshitomo Ishii ◽  
Junki Suzuki ◽  
Takuro Bessyo ◽  
Naoki Watanabe
Keyword(s):  
Grain Boundaries ◽  
Polycrystalline Silicon ◽  
Solid Phase ◽  
Raman Microscopy ◽  
Laser Crystallization ◽  
Local Vibration ◽  
Optical Phonon Mode ◽  
Glass Substrates ◽  
Silicon Thin Films ◽  
Si Films

Raman microscopy was applied to characterize polycrystalline silicon (poly-Si) on glass substrates for application as thin-film transistors (TFTs) integrated on electronic display panels. This study examines the crystallographic defects and stress in poly-Si films grown by industrial techniques: solid phase crystallization and excimer laser crystallization (ELC). To distinguish the effects of defects and stress on the optical-phonon mode of the Si–Si bond, a semiempirical analysis was performed. The analysis was compared with defect images obtained through electron microscopy and atomic force microscopy. It was found that the Raman intensity for the ELC film is remarkably enhanced by the hillocks and ridges located around grain boundaries, which indicates that Raman spectra mainly reflect the situation around grain boundaries. A combination of the hydrogenation of films and the observation of the Si-hydrogen local-vibration mode is useful to support the analysis on the defects. Raman microscopy is also effective for detecting the plasma-induced damage suffered during device processing and characterizing the performance of Si layer in TFTs.

Development of CdTe on Si Heteroepilayers for Controlled PV Material and Device Studies

2013 ◽  
Vol 1538 ◽  
pp. 243-248 ◽  
Author(s):  
T.A. Gessert ◽  
R. Dhere ◽  
D. Kuciauskas ◽  
J. Moseley ◽  
H. Moutinho ◽  
...  
Keyword(s):  
Open Circuit ◽  
Focal Plane Arrays ◽  
Structural Quality ◽  
Extended Defects ◽  
Large Area ◽  
Recombination Rates ◽  
High Quality ◽  
Crystalline Materials ◽  
The University ◽  
Thermal Preparation

ABSTRACTThe objective of the National Renewable Energy Laboratory’s (NREL) current three-year CdTe plan under the U.S. Department of Energy’s SunShot Initiative is to identify primary mechanisms that limit the open-circuit voltage and fill factor of polycrystalline CdTe photovoltaic (PV) devices, and develop CdTe synthesis processes and/or device designs that avoid these limitations. Part of this project relies on analysis of crystalline materials and pseudocrystalline CdTe layers where point and extended defects can be introduced sequentially without the complications of extensive impurities and grain boundaries that are typical of present polycrystalline films. The ultimate goals of the project include producing CdTe PV devices that demonstrate ≥20% conversion efficiency, while significantly improving our understanding of processes and materials capable of attaining cost goals of <$0.50 per watt. While NREL is investigating several options for the routine fabrication of high-quality CdTe layers, one pathway involves CdTe molecular beam heteroepitaxy (MBE) on Si in collaboration with the University of Illinois at Chicago. Although CdTe/Si heteroepitaxy is relatively unfamiliar to researchers in the PV community, it has been used successfully for more than 20 years to produce high-quality CdTe surfaces required for commercial production of large-area single-crystal HgCdTe infrared detectors and focal-plane arrays. The process involves chemical and thermal preparation of Si (211) wafers, followed by deposition of As-passivation and ZnTeaccommodation layers. MBE-grown CdTe layers deposited on top of this “template” have been shown to demonstrate low etch-pit density (EPD, preferably ≤ ∼5x105 cm-2) and high structural quality (full width at half maximum ∼ 60 arcs). These initial studies indicate that 10-μm-thick CdTe layers on Si are indeed epitaxial with cathodoluminescence-determined dislocation density consistent with historic EPD measurements, and that recombination rates are distinct from either as-deposited polycrystalline or crystalline materials.

Microcrystalline Silicon Thin Films and Triple-Junction Solar Cells

2012 ◽  
Vol 468-471 ◽  
pp. 1912-1915
Author(s):  
Hui Zhi Ren ◽  
Ying Zhao ◽  
Xiao Dan Zhang ◽  
Hong Ge ◽  
Zong Pan Wang
Keyword(s):  
Thin Films ◽  
Solar Cells ◽  
Triple Junction ◽  
Microcrystalline Silicon ◽  
Large Area ◽  
High Quality ◽  
Area Efficiency ◽  
Silicon Thin Films ◽  
Deposition Parameters ◽  
Area Deposition

We report on microcrystalline silicon thin films and a-Si:H/a-SiGe:H/μc-Si:H triple-junction p-i-n solar cells deposited on large-area glass substrate. Microcrystalline silicon (μc-Si:H) bottom cells were deposited at a VHF-PECVD deposition system with 40.68MHz. It is necessary to develop the uniformity of μc-Si:H thin films for large-area deposition of high-quality triple-junction solar cells. By optimizing the deposition parameters, μc-Si:H thin films have been obtained with good thickness and very good crystalline volume fractions uniformity over the whole substrates area. The triple-junction module have been successful fabricated. The best module on 0.79 m2 size substrates has an initial total-area efficiency of 8.35%.

Ni-Induced Selective Nucleation and Solid Phase Epitaxy of Large-Grained Poly-Si on Glass

1999 ◽  
Vol 587 ◽  
Author(s):  
Rosaria A. Puglisi ◽  
Hiroshi Tanabe ◽  
Claudine M. Chen ◽  
Harry A. Atwater ◽  
Emanuele Rimini
Keyword(s):  
Amorphous Silicon ◽  
Polycrystalline Silicon ◽  
Crystalline Silicon ◽  
Solid Phase ◽  
Silicon Film ◽  
Crystallization Rate ◽  
Silicon Films ◽  
Solid Phase Epitaxy ◽  
Tem Analysis ◽  
Glass Substrates

AbstractWe investigated the formation of large-grain polycrystalline silicon films on glass substrates for application in low-cost thin film crystalline silicon solar cells. Since use of glass substrates constrains process temperatures, our approach to form large-grain polycrystalline silicon templates is selective nucleation and solid phase epitaxy (SNSPE). In this process, selective crystallization of an initially amorphous silicon film, at lithographically predetermined sites, enables grain sizes larger than those observed via random crystallization. Selective heterogeneous nucleation centers were created on undoped, 75 nm thick, amorphous silicon films, by masked implantation of Ni islands, followed by annealing at temperatures below 600 °. At this temperature, the Ni precipitates into NiSi2 particles that catalyze the transition from the amorphous to the crystalline Si phase. Seeded crystallization begins at the metal islands and continues via lateral solid phase epitaxy (SPE), thus obtaining crystallized regions of several tens of square microns in one hour. We have studied the dependence of the crystallization rate on the Ni-implanted dose in the seed, in the 5×1015/cm3 - 1016/cm3range. The large grained polycrystalline Si films were then used as a substrate for molecular beam epitaxy (MBE) depositions of 1 [.proportional]m thick Si layers. Transmission electron microscopy (TEM) analysis showed a strong correlation between the substrate morphology and the deposited layer. The layer presented a large grain morphology, with sizes of about 4 [.proportional]m.

High Quality GaAs on Soi by MOCVD

1989 ◽  
Vol 160 ◽  
Author(s):  
N.H. Karam ◽  
V. Haven ◽  
S. Vernon ◽  
J. Ramdani ◽  
N. El-Masry ◽  
...  
Keyword(s):  
Thermal Cycle ◽  
Defect Density ◽  
Fold Increase ◽  
Gate Length ◽  
Photoluminescence Intensity ◽  
Large Area ◽  
High Quality ◽  
Cycle Growth ◽  
Gaas Films ◽  
Low Temperature Photoluminescence

AbstractEpitaxial GaAs films have been successfully deposited on three-inch Si wafers with a buried oxide by MOCVD. The SOI wafers were prepared using Separation by IMplantation of OXygen (SIMOX) process. High quality GaAs on SIMOX films, with dislocation density in the range of 2–6 × 106 cm-2, have been achieved using Thermal Cycle Growth (TCG) deposition technique. These films showed a 50-fold increase in the low temperature photoluminescence intensity over conventional deposition. We have also fabricated MESFET’s in GaAs on SIMOX with performance comparable to those fabricated in GaAs. The maximum measured transconductance was in the range of 175-180 ms/mm at a 1.5 µm gate length and a 5 µm source to drain separation. This is the first demonstration of large area, high quality and low defect density GaAs on SIMOX.

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