• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.66 no.5
• /
• pp.851-856
• /
• 2017

Research on the edge isolation process of typical polycrystalline silicon solar cells was carried out using laser scribing equipment. The voltage-current characteristics of the solar cell before and after laser scribing were analyzed using a solar simulator. Current density and efficiency increased as the fill factor of the solar cell remained constant after the laser scribing process. The efficiency of the solar cell can be increased in a short time by the edge isolation process performed via a laser scribing process. The polycrystalline silicon solar cell was made into a series electrode, and the efficiency of the solar cell increased because the width of the solar cell was narrowed and the active region was widened by the laser scribing process.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.25 no.5
• /
• pp.362-367
• /
• 2016

Recently, wireless charging systems have expanded their applications from household electrical appliances to outdoor activity devices. In wireless charging systems, solar cells have versatile advantages, such as abundant raw materials within the earth, reasonable prices of products, and highest power conversion efficiency. In this study, the photovoltaic effect between a silicon solar cell and a photon of infrared wavelength was simulated using a Shockley diode equation. A solar cell power charging system was then set up to: 1) clarify mechanisms of the charging interaction based on the photovoltaic effect with a laser source, and 2) verify interdependency of the parameters: laser settings and geometrical position between a solar cell and the laser. As was observed, the solar cell generates more power when the photon was irradiated uniformly, intensively, and vertically on the surface of the solar cell.

• Laser Solutions
• /
• v.14 no.3
• /
• pp.1-6
• /
• 2011

Globally, the interest of renewable energy has become an upsurge. Especially, the solar industry is the one which is getting rapid growth rate. Many of researchers have been undertaking to improve the efficiency of solar cell to accomplish grid parity. The most of research has been concentrated on two methods, one on the selective emitter and the other is on LBSF (Local Back Surface Field) formation. Laser patterning will be needed to eliminate the thin film to form selective emitter and LBSF of solar cell. This paper reports some experimental results in laser patterning process for high-efficiency crystalline solar cell manufacturing. The experimental results indicate that the patterning quality depends on the average power and repetition rate of laser. The experimental results prove that the laser patterning process is an advantageous method to improve the efficiency of solar cell.

• Journal of the Korean Solar Energy Society
• /
• v.31 no.4
• /
• pp.103-111
• /
• 2011

Laser drilling of vias is the one of key technologies in developing Emitter-Wrap Through(EWT) solar cell which is particularly attractive due to the use of industrial processing and common solar grade p-type silicon materials. While alternative economically feasible drilling process is not available to date, the processing time and laser induced damage should be as small as possible in this process. This paper provides an overview on various factors that should be considered in using the laser via drilling technology for developing highly efficient and industrially applicable EWT solar cells.

• Current Optics and Photonics
• /
• v.6 no.6
• /
• pp.627-633
• /
• 2022

To realize uniform side pumping of solar lasers and improve their output power, a solar concentrating system based on off-axis parabolic mirrors is proposed. Four identical off-axis parabolic mirrors with focal length of 1,000 mm are toroidally arranged as the primary concentrator. Four two-dimensional compound parabolic concentrators (2D-CPCs) are designed as a secondary concentrator to further compress the focused spot induced by the parabolic mirrors, and the focused light is then homogenized by four rectangular diffusers and provides uniform pumping for a laser-crystal rod to achieve solar laser emission. Simulation results show that the solar power received by the laser rod, uniformity of the light spot, and output power of the solar laser are 7,872.7 W, 98%, and 351.8 W respectively. This uniform pumping configuration and concentrator design thus provide a new means for developing high-power side-pumped solid-state solar lasers.

• 한국신재생에너지학회:학술대회논문집
• /
• 2009.11a
• /
• pp.364-364
• /
• 2009

The solar cell is in the spotlight as a future green energy source. In the solar cells based on silicon wafer, the improvement of efficiency is one of crucial issues. One of techniques for high efficiency is texturing on the surface of solar cells. We studied the laser texturing on the surface of multi-crystalline silicon solar cells. The laser texturing followed by chemical etching is adequate for the multi-crystalline structure which have random crystallographic directions. We used the fiber laser for texturing and the SiNx as a masking layer for etching process. We investigated the shapes of holes for texturing in the various laser power conditions and analyzed the holes after removal of thermal damages caused by laser ablation through a 3D profiler.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 1995.05a
• /
• pp.154-159
• /
• 1995

To achieve a high aspect ration of metal contact, buried contact solar cell scribe the silicon surface using laser. The Q-switched NdLYAG laser which has 1.064$\mu\textrm{m}$ wavelength use for silicon scribing with 25~40$\mu\textrm{m}$ width and 20~200$\mu\textrm{m}$ depth capabilities. The 2~3% shading losses are very low campared to the screen printing solar cell. In this paper, we investigate the silicon scribing theory and pratice, scribing system for BCSC processing.

• Laser Solutions
• /
• v.14 no.4
• /
• pp.9-13
• /
• 2011

The solar panel that consists of copper plate and copper tube was successfully welded by ultrasonic seam welding. However it was not only expensive the copper material but also ultrasonic welding has many problem such as high error rate, difficulty of dissimilar material welding, noise, etc. At this study, the laser welding of solar panel with aluminum plate instead of copper. The welding were carried out with the pulsed Nd:YAG laser and the weld bead geometry was measured with the variation of pulse energy. Consequently, there was no difference between the ultrasonic and the laser welding on the performance of heat transfer capacities. Also the formation of intermetalic compound such as CuAl2 was increased with the pulse energy.

• 한국신재생에너지학회:학술대회논문집
• /
• 2010.06a
• /
• pp.58.1-58.1
• /
• 2010

In solar cell module manufacturing, single solar cells has to be joined electrically to strings. Copper stripes coated with tin-silver-copper alloy are joined on screen printed silver of solar cells which is called busbar. The bus bar collects the electrons generated in solar cell and it is connected to the next cell in the conventional module manufacturing by a metal stringer using conventional hot air or infrared lamp soldering systems. For thin solar cells, both soldering methods have disadvantages, which heats up the whole cell to high temperatures. Because of the different thermal expansion coefficient, mechanical stresses are induced in the solar cell. Recently, the trend of solar cell is toward thinner thickness below 180um and thus the risk of breakage of solar cells is increasing. This has led to the demand for new joining processes with high productivity and reduced error rates. In our project, we have developed a new method to solder solar cells with a laser heating source. The soldering process using diode laser with wavelength of 980nm was examined. The diode laser used has a maximum power of 60W and a scanner system is used to solder dimension of 6" solar cell and the beam travel speed is optimized. For clamping copper stripe to solar cell, zirconia(ZrO)coated iron pin-spring system is used to clamp both joining parts during a scanner system is traveled. The hot plate temperature that solar cell is positioned during lasersoldering process is optimized. Also, conventional solder joints after $180^{\circ}C$ peel tests are compared to the laser soldering methods. Microstructures in welded zone shows that the diffusion zone between solar cell and metal stripes is better formed than inIR soldering method. It is analyzed that the laser solder joints show no damages to the silicon wafer and no cracks beneath the contact. Peel strength between 4N and 5N are measured, with much shorter joining time than IR solder joints and it is shown that the use of laser soldering reduced the degree of bending of solar cell much less than IR soldering.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.33 no.4
• /
• pp.291-296
• /
• 2020

The high power of a shingled photovoltaic module can be attributed to its low cell-to-module loss. The production of high power modules in limited area requires high efficiency solar cells. Shingled photovoltaic modules can be made by divided solar cells, which can be produced by the laser scribing process. After dividing the 21% PERC cell using laser scribing, the efficiency decreased by approximately 0.35%. However, there was no change in the efficiency of the solar cell having relatively lower efficiency, because the laser scribing process induce higher heat damages in solar cells with high efficiency. To prove this phenomena, the J₀ (leakage current density) of each cell was analyzed. It was found that the J₀ of 21% PERC increased about 17 times between full and divided solar cell. However, the J₀ of 20.2% PERC increased only about 2.5 times between full and divided solar cell.