The development in solar PV technology is growing very fast in recent years due to technological improvement, cost reductions in materials and government support for renewable energy based electricity production. Photovoltaic is playing an important role to utilize solar energy for electricity production worldwide. At present, the PV market is growing rapidly with worldwide around 23.5 GW in 2010 and also growing at an annual rate of 35–40%, which makes photovoltaic as one of the fastest growing industries. The efficiency of solar cell is one of the important parameter in order to establish this technology in the market. Presently, extensive research work is going for efficiency improvement of solar cells for commercial use. The efficiency of monocrystalline silicon solar cell has showed very good improvement year by year. It starts with only 15% in 1950s and then increase to 17% in 1970s and continuously increase up to 28% nowadays. The growth in solar photovoltaic technologies including worldwide status, materials for solar cells, efficiency, factor affecting the performance of PV module, overview on cost analysis of PV and its environmental impact are reviewed in this paper.

Progress in solar PV technology: Research and achievement

The fill factor of silicon wafer solar cells is strongly influenced by recombination currents and ohmic resistances. A practical upper limit for the fill factor of crystalline silicon solar cells operating under low-level injection is set by recombination in the quasi-neutral bulk and at the two cell surfaces. Series resistance, shunt resistance, and additional recombination currents further lower the fill factor. For process optimization or loss analysis of solar cells, it is important to determine the influence of both ohmic and recombination loss mechanisms on the fill factor. In this paper, a method is described to quantify the loss in fill factor due to series resistance, shunt resistance, and additional recombination currents. Only the 1-Sun J-V curve, series resistance at the maximum power point, and shunt resistance need to be determined to apply the method. Application of the method is demonstrated on an 18.4% efficient inline-diffused p-type silicon wafer solar cell and a 21.1% efficient heterojunction n-type silicon wafer solar cell. Our analysis does not require J-V curve fitting to extract diode saturation current densities or ideality factor; however, the results are shown to be consistent with curve fitting results if the cell's two-diode model parameters can be unambiguously determined by curve fitting.

A Fill Factor Loss Analysis Method for Silicon Wafer Solar Cells

Screen printing is a potential technique for mass-production of printed electronics; however, improvement in printing resolution is needed for high integration and performance. In this study, screen printing of highly loaded silver ink (77 wt %) on polyimide films is studied using fine-scale silicon stencils with openings ranging from 5 to 50 μm wide. This approach enables printing of high-resolution silver lines with widths as small as 22 μm. The printed silver lines on polyimide exhibit good electrical properties with a resistivity of 5.5×10(-6) Ω cm and excellent bending tolerance for bending radii greater than 5 mm (tensile strains less than 0.75%).

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Screen Printing of Highly Loaded Silver Inks on Plastic Substrates Using Silicon Stencils

A silver molecular ink platform formulated for screen, inkjet, and aerosol jet printing is presented. A simple formulation comprising silver neodecanoate, ethyl cellulose, and solvent provides improved performance versus that of established inks, yet with improved economics. Thin, screen-printed traces with exceptional electrical (<10 mΩ/□/mil or 12 μΩ·cm) and mechanical properties are achieved following thermal or photonic sintering, the latter having never been demonstrated for silver-salt-based inks. Low surface roughness, submicron thicknesses, and line widths as narrow as 41 μm outperform commercial ink benchmarks based on flakes or nanoparticles. These traces are mechanically robust to flexing and creasing (less than 10% change in resistance) and bind strongly to epoxy-based adhesives. Thin traces are remarkably conformal, enabling fully printed metal–insulator–metal band-pass filters. The versatility of the molecular ink platform enables an aerosol jet-compatible ink that yields conductive features...

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Versatile Molecular Silver Ink Platform for Printed Flexible Electronics

A solar cell and a method of manufacturing the same are disclosed. The solar cell includes a substrate of a first conductive type having at least one via hole; an emitter layer only on at least a portion of the via hole and at least one selected from a group consisting of an incident surface and side surfaces of the substrate, the emitter layer having a second conductive type opposite the first conductive type; at least one first electrode on the incident surface, the first electrode being electrically connected to the emitter layer; a second electrode connected to an opposite surface to the incident surface; and at least one first electrode current collector on the opposite surface, the at least one first electrode current collector being insulated from the second electrode and being electrically connected to the at least one first electrode through the via hole.

Solar cell and method of manufacturing the same

Impact of boron doping profiles on the specific contact resistance of screen printed Ag–Al contacts on silicon

Impact of screen printing silver paste components on the space charge region recombination losses of industrial silicon solar cells

https://www.uni-ulm.de/fileadmin/website_uni_ulm/hrem/publications/2013/Hoenig2013b.pdf

Rene Hoenig

Papers

Impact of boron doping profiles on the specific contact resistance of screen printed Ag–Al contacts on silicon

Impact of screen printing silver paste components on the space charge region recombination losses of industrial silicon solar cells

The Nature of Screen Printed Front Side Silver Contacts - Results of the project MikroSol

New measurement method for the investigation of space charge region recombination losses induced by the metallization of silicon solar cells

Industrially feasible multi-crystalline metal wrap through (MWT) silicon solar cells exceeding 16% efficiency