• The Transactions of the Korean Institute of Electrical Engineers C
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• v.55 no.12
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• pp.565-569
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• 2006

Plasma enhanced chemical vapor deposition(PECVD) is a well established technique for the deposition of hydrogenated film of silicon nitride (SiNx:H), which is commonly used as an antireflection coating as well as passivating layer in crystalline silicon solar cell. PECVD-SiNx:H films were investigated by varying the deposition and annealing conditions to optimize for the application in silicon solar cells. By varying the gas ratio (ammonia to silane), the silicon nitride films of refractive indices 1.85 - 2.45 were obtained. The film deposited at $450^{\circ}C$ showed the best carrier lifetime through the film deposition rate was not encouraging. The film deposited with the gas ratio of 0.57 showed the best carrier lifetime after annealing at a temperature of $800^{\circ}C$. The single crystalline silicon solar cells fabricated in conventional industrial production line applying the optimized film deposition and annealing conditions on large area substrate of size $125mm{\times}125mm$ (pseudo square) was found to have the conversion efficiencies as high as 17.05 %. Low cost and high efficiency silicon solar cells fabrication sequence has also been explained in this paper.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.29 no.6
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• pp.370-375
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• 2016

In this paper, we investigated the electrical properties of crystalline silicon solar cell fabricated with Ni/Cu/Ag plating. The laser process was used to ablate silicon nitride layer as well as to form the selective emitter. Phosphoric acid layer was spin-coated to prevent damage caused by laser and formed selective emitter during laser process. As a result, the contact resistance was decreased by lower sheet resistance in electrode region. Low sheet resistance was obtained by increasing laser current, but efficiency and open circuit voltage were decreased by damage on the wafer surface. KOH treatment was used to remove the laser damage on the silicon surface prior to metalization of the front electrode by Ni/Cu/Ag plating. Ni and Cu were plated for each 4 minutes and 16 minutes and very thin layer of Ag with $1{\mu}m$ thickness was plated onto Ni/Cu electrode for 30 seconds to prevent oxidation of the electrode. The silicon solar cells with KOH treatment showed the 0.2% improved efficiency compared to those without treatment.

• 한국태양에너지학회:학술대회논문집
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• 2009.11a
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• pp.350-355
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• 2009

The crysralline silicon solar cell where the solar cell market grows rapidly is occupying of about 85% or more high efficiency and low cost endeavors many crystalline solar cells. The fabricaion process of high efficiency crystalline silicon solar cells necessitate complicated fabrication processes and Ti/Pd/AG contact, This metal contacts have only been used in limited areas in spite of their good srability and low contact resistance because of expensive materials and process. Commercial solar cells with screen-printed solar cells formed by using Ag paste suffer from loe fill factor and high contact resistance and low aspect ratio. Ni and Cu metal contacts have been formed by using electroless plating and light-induced electro plating techniques to replace the Ti/Pd/Ag and screen-printed Ag contacts. Copper and Silver can be plated by electro & light-induced plating method. Light-induced plating makes use the photovoltaic effect of solar cell to deposit the metal on the front contact. The cell is immersed into the electrolytic plating bath and irradiated at the front side by light source, which leads to a current density in the front side grid. Electroless plated Ni/ Electro&light-induced plated Cu/ Light-induced plated Ag contact solar cells result in an energy conversion efficiency of 16.446 % on 0.2~0.6${\Omega}$ cm, $20{\times}20mm^2$, CZ(Czochralski) wafer.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.34 no.6
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• pp.433-437
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• 2021

As the demand for new and renewable energy increases due to the depletion of fossil fuels, solar power generation, a core energy source for new and renewable energy, requires research on solar modules for high output power generation. In this paper, the electrical characteristics of solar cell strip at the edge and in the center of single-crystal silicon having a semi-square shape were analyzed. The cell strip located in the center showed the efficiency increase by 0.26% compared to the cell strip at the edge of the solar cell. A shingled photovoltaic module was manufactured for each cell strip. As a result, the output power of the module using the cell strip located in the center was higher by 0.992%.

• Transactions on Electrical and Electronic Materials
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• v.4 no.5
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• pp.10-14
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• 2003

A low-cost, large area, random, maskless texturing scheme independent of crystal orientation is expected to have significant impact on terrestrial photovoltaic technology. We investigated silicon surface microstructures formed by reactive ion etching (R IE) in Multi-Hollow cathode system. Desirable texturing effect has been achieved when radio-frequency (rf) power of about 20 Watt per one hollow cathode glow is applied for our RF Multi -Hollow cathode system. The black silicon etched surface shows almost zero reflectance in the visible region as well as in near IR region. The etched silicon surface is covered by columnar microstructures with diameters from 50 to 100 nm and depth of about 500 nm. We have successfully achieved 11.7 % efficiency of mono-crystalline silicon solar cell and 10.2 % for multi-crystalline silicon solar cell.

• Journal of the Semiconductor & Display Technology
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• v.11 no.2
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• pp.7-11
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• 2012

SiNx films have been wildly used as anti-reflection coatings and passivation for crystalline silicon solar cells. In this study, the SiNx films were deposited by using high frequency (13.56MHz) PECVD and optical & passivation properties were investigated. The RF power was changed in a certain range for the film deposition. Then, the refractive index, etch rate, minority carrier lifetime and cell efficiency were measured to study the properties of the film respectively. The optimal deposition conditions for application to crystalline silicon solar cells were proposed as results of the study. Finally, the best cell efficiency of 16.98% was obtained from the solar cell with the SiNx films deposited by RF power of 550W.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.270-270
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• 2009

The surface texturing technology is one of the methods to improve the efficiency of crystalline silicon solar cell. This process reduced the reflectance at the surface by the so-called double bounce effect and increased the light trapping. Among these surface texturing technology, the laser texturing is effective for multi-crystalline silicon solar cells which have random crystallographic directions. We investigated the characteristics of laser processing on the surface of the multi-crystalline silicon solar cells using the fiber laser.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1995.05a
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• pp.172-176
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• 1995

Schemes to trap weakly absorbed light into the cell have played an important role in improving the efficiency of both amorphous and crystlline silicon solar cells. One class of scheme relies on randomizing the direction of light within the cell by use of Lambertian(diffuse)surfaces. A second class of scheme relies on the use fo well defined geometrical features to control the direction of light wihin the cell, Widly used geometrical features in crystalline silicon solar cells are the square based pyramids and V-shaped grooves formed in (100) orientated surfaces by intersecting(III) crystallographic planes exposed by anisotropic etching. 18.5% conversion efficiency of Buried Contact Solar Cell with pyramidally textured surface has been achieved. 18.5% efficiency of silicon solar cell is one the highest record in the world The efficieny of cell without textured surface was 16.6%, When adapting textured surface to the Cell, the efficiency has been improved over 12%.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.43.1-43.1
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• 2010

In the crystalline silicon solar cells, the full area aluminum_back surface field(BSF) is routinely achieved through the screen-printing of aluminum paste and rapid firing. It is widely used in the industrial solar cell because of the simple and cost-effective process to suppress the overall recombination at the back surface. However, it still has limitations such as the relatively higher recombination rate and the low-to-moderate reflectance. In addition, it is difficult to apply it to thinner substrate due to wafer bowing. In the recent years, the dielectric back-passivated cell with local back contacts has been developed and implemented to overcome its disadvantages. Although it is successful to gain a lower value of surface recombination velocity(SRV), the series resistance($R_{series}$) becomes even more important than the conventional solar cell. That is, it is a trade off relationship between the SRV and the $R_{series}$ as a function of the contact size, the contact spacing and the geometry of the opening. Therefore it is essential to find the best compromise between them for the high efficiency solar cell. We have investigated the optimal design for the local back contact by using PC1D simulation.

• Solar Energy
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• v.8 no.2
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• pp.73-76
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• 1988

Thick films based on the mature crystalline silicon technology are expected to exhibit eversmaller cost reduction. The thin-film-based technology is, however, expected to exhibit a much sharper drop in cost as it develops. In this report, technology and recent R & D of thin film solar cell, such as amorphous silicon, cadnium telluride, copper indium diselenide and gallium arsenide, are described. Perspectives of world photovoltaic market and solar cell price are also described.