Optical properties and Limits of a Large-Area Periodic Nanophotonic Light Trapping Design for Polycrystalline Silicon Thin Film Solar Cells

2013 ◽  
Vol 1493 ◽  
pp. 59-64 ◽  
Author(s):  
Daniel Lockau ◽  
Tobias Sontheimer ◽  
Veit Preidel ◽  
Christiane Becker ◽  
Florian Ruske ◽  
...  
Keyword(s):  
Crystalline Silicon ◽  
Solid Phase ◽  
Light Trapping ◽  
Optical Design ◽  
Silicon Layer ◽  
Electron Beam Evaporation ◽  
Large Area ◽  
Silicon Thin Film ◽  
Material Loss ◽  
Glass Substrates

ABSTRACTRigorous finite element optical simulations have been used to examine the absorption of light in various crystalline silicon based, nanostructured solar cell architectures. The compared structures can all be produced on glass substrates using a periodically structured dielectric coating and a combination of electron-beam evaporation of silicon and subsequent solid phase crystallization. A required post-treatment by selective etching of non-compact silicon regions results in an absorber material loss. We show that by adequately tailoring the optical design around the processed silicon layer, the absorptance loss due to material removal can be completely overcome. The resulting silicon structure, which is an array of holes with non-vertical sidewalls, shows promising light path enhancement and features an even higher absorptance than the initial nanodome structure of the unetched absorber.

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.

Light Scattering by Textured Al-Doped Zinc Oxide Film for Thin Film Silicon Solar Cells Coated on Glass Substrates

2012 ◽  
Vol 509 ◽  
pp. 279-287
Author(s):  
Deng Kui Miao ◽  
Qing Nan Zhao ◽  
Yu Hong Dong ◽  
Wen Hui Yuan ◽  
Lei Wu ◽  
...  
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Light Scattering ◽  
Electrical Properties ◽  
Light Trapping ◽  
Zinc Oxide Film ◽  
Silicon Thin Film ◽  
Glass Substrates ◽  
Ceramic Targets ◽  
Sputtering System

ZnO:Al thin films were deposited on low-iron glass substrates (size: 1100×1400 mm2 ) in an in-line sputtering system, using ZnO:Al ceramic targets. The initially smooth films exhibit high transparencies (T≥85% for visible light) and excellent electrical properties (carrier concentration N=3.810×1020cm-3, mobility μ=20.47 cm2/V•s). The films, etched by diluted HCl for different time, appear roughness morphology with suitable angles and crater structure, used for controlling the light scattering properties of the textured ZnO:Al films. Moreover, the electrical properties are not affected by the etching process. Thus, it is possible to optimize separately the electro-optical and light trapping properties. The textured ZnO:Al films (haze 21.2%, 550 nm) were used as front contacts for amorphous silicon thin film solar cells prepared by PECVD, 6.5% conversion efficiency were obtained.

Preferential crystal growth of germanium by solid phase crystallization

2014 ◽  
Vol 92 (7/8) ◽  
pp. 576-581 ◽  
Author(s):  
Mikuri Kanai ◽  
Yuji Kojima ◽  
Masao Isomura
Keyword(s):  
Crystalline Silicon ◽  
Solid Phase ◽  
Electron Beam Evaporation ◽  
High Density ◽  
Solid Phase Crystallization ◽  
Air Exposure ◽  
Preferential Growth ◽  
Practical Applications ◽  
Si Substrates ◽  
P Type

We have investigated the preparation of crystalline germanium films by the solid phase crystallization (SPC) of amorphous germanium (a-Ge) precursor on single crystalline silicon substrates. The a-Ge precursor easily incorporates the impurities from the surface exposed to the air, and the impurities affect the crystallinity after the SPC. In the a-Ge precursor prepared by Knudsen-cell evaporation, the preferential crystalline growth following the Si substrates is disturbed by the high density of impurities and the random crystalline structures are formed. The a-Ge precursors prepared by electron beam evaporation have high impurity concentrations only near the surface because the impurity diffusion is slow because of the relatively high density. The preferential growth is successfully obtained in a-Ge precursor prepared on n-type Si substrates, although the random crystallization is slightly observed on p-type Si substrates. By sufficiently reducing the impurity concentrations by avoiding the air exposure, the preferential growth can be promoted on p-type Si substrates. The impurity incorporation because of the air exposure is sufficiently reduced for the preferential growth by covering a-Ge with a-Si blocking layers. This method is effective for future practical applications of SPC Ge films.

PREPARATION OF ADHERENT MnSix FILMS

2002 ◽  
Vol 16 (07) ◽  
pp. 205-215 ◽  
Author(s):  
Q. R. HOU ◽  
Z. M. WANG ◽  
Y. B. CHEN ◽  
Y. J. HE
Keyword(s):  
Electron Beam ◽  
Substrate Temperature ◽  
Thermal Evaporation ◽  
Solid Phase ◽  
Electron Beam Evaporation ◽  
Solid Phase Reaction ◽  
Phase Reaction ◽  
Reactive Deposition ◽  
Glass Substrates ◽  
Manganese Silicide

The adhesion of manganese silicide ( MnSi x) films on silicon and glass substrates is studied by using the micro-scratch method. The films were prepared by electron beam evaporation and thermal evaporation. To improve adhesion of the films, several techniques including ion bombardment, increasing substrate temperature, and insertion of a silicon intermediate layer were used. Finally, adherent MnSi x(x~1.7) films were prepared through solid phase reaction as well as reactive deposition. The hardness and modulus of the MnSi x(x~1.7) film were measured by a nano-indenter and the values are 8.8±1.0 GPa and 141±15 GPa, respectively.

Efficient light trapping for maskless large area randomly textured glass structures with various haze ratios in silicon thin film solar cells

Solar Energy ◽  
2018 ◽  
Vol 173 ◽  
pp. 1173-1180 ◽  
Author(s):  
Shahzada Qamar Hussain ◽  
Anh Huy Tuan Le ◽  
Kumar Mallem ◽  
Hyeongsik Park ◽  
Minkyu Ju ◽  
...  
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Light Trapping ◽  
Thin Film Solar Cells ◽  
Large Area ◽  
Silicon Thin Film

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.

Extremely Low Temperature Silicon Liquid Phase Epitaxy

1995 ◽  
Vol 386 ◽  
Author(s):  
M. Konuma ◽  
I. Silier ◽  
A. Gutjahr ◽  
E. Bauser ◽  
F. Banhart ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Liquid Phase Epitaxy ◽  
Hydrofluoric Acid ◽  
Crystalline Silicon ◽  
Silicon Layer ◽  
Extended Defects ◽  
Glass Substrates ◽  
Nano Crystalline ◽  
Amorphous Glass ◽  
Substrate Surfaces

ABSTRACTBy liquid phase epitaxy (LPE) we have grown silicon layers on silicon and partially masked silicon at temperatures below 450 °C from Ga and Ga-In solutions. Oxidation of the cleaned silicon substrate surfaces before epitaxial growth has been prevented by a buffered hydrofluoric acid treatment. The epitaxial layers reached a thickness of 7 jim and were free of extended defects.Low growth temperatures make it possible to grow silicon layers also on pre-treated glass substrates. The amorphous glass is first coated with a thin nano-crystalline silicon layer which is deposited by plasma processes from a mixture of SiH4/H2 gas. The grains in the silicon layers grown from Ga solution on glass have reached sizes up to 100 μm.

scholarly journals Advances in Evaporated Solid-Phase-Crystallized Poly-Si Thin-Film Solar Cells on Glass (EVA)

2008 ◽  
Vol 2008 ◽  
pp. 1-10 ◽  
Author(s):  
O. Kunz ◽  
Z. Ouyang ◽  
J. Wong ◽  
A. G. Aberle
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Solid Phase ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Device Fabrication ◽  
Thin Film Solar Cells ◽  
Large Area ◽  
Silicon Thin Film ◽  
Numerical Device

Polycrystalline silicon thin-film solar cells on glass obtained by solid-phase crystallization (SPC) of PECVD-deposited a-Si precursor diodes are capable of producing large-area devices with respectable photovoltaic efficiency. This has not yet been shown for equivalent devices made from evaporated Si precursor diodes (“EVA” solar cells). We demonstrate that there are two main problems for the metallization of EVA solar cells: (i) shunting of the p-n junction when the air-side metal contact is deposited; (ii) formation of the glass-side contact with low contact resistance and without shunting. We present a working metallization scheme and first current-voltage and quantum efficiency results of 2 cm2 EVA solar cells. The best planar EVA solar cells produced so far achieved fill factors up to 64%, series resistance values in the range of 4-5 Ωcm2, short-circuit current densities of up to 15.6 mA/cm2, and efficiencies of up to 4.25%. Using numerical device simulation, a diffusion length of about 4 μm is demonstrated for such devices. These promising results confirm that the device fabrication scheme presented in this paper is well suited for the metallization of EVA solar cells and that the electronic properties of evaporated SPC poly-Si materials are sufficient for PV applications.

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