• Current Photovoltaic Research
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• v.4 no.2
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• pp.54-58
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• 2016

Laser-doped selective emitter process requires dopant source deposition, spin-on-glass, and is able to form selective emitter through SiNx layer by laser irradiation on desired locations. However, after laser doping process, the remaining dopant layer needs to be washed out. Laser-induced melting of pre-deposited impurity doping is a precise selective doping method minimizing addition of process steps. In this study, we introduce a novel scheme for fabricating highly efficient selective emitter solar cell by laser doping. During this process, laser induced damage induces front contact destabilization due to the hindrance of silver nucleation even though laser doping has a potential of commercialization with simple process concept. When the laser induced damage is effectively removed using solution etch back process, the disadvantage of laser doping was effectively removed. The devices fabricated using laser doping scheme power conversion efficiency was significantly improved about 1% abs. after removal the laser damages.

• Current Photovoltaic Research
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• v.7 no.4
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• pp.111-120
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• 2019

The output power of a crystalline silicon (c-Si) photovoltaic (PV) module is not directly the sum of the powers of its unit cells. There are several losses and gain mechanisms that reduce the total output power when solar cells are encapsulated into solar modules. Theses factors are getting high attention as the high cell efficiency achievement become more complex and expensive. More research works are involved to minimize the "cell-to-module" (CTM) loss. Our paper is aimed to focus on electrical losses due to interconnection and mismatch loss at PV modules. Research study shows that among all reasons of PV module failure 40.7% fails at interconnection. The mismatch loss in modern PV modules is very low (nearly 0.1%) but still lacks in the approach that determines all the contributing factors in mismatch loss. This review paper is related to study of interconnection loss technologies and key factors contributing to mismatch loss during module fabrication. Also, the improved interconnection technologies, understanding the approaches to mitigate the mismatch loss factors are precisely described here. This research study will give the approach of mitigating the loss and enable improvement in reliability of PV modules.

• Korean Journal of Microbiology
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• v.43 no.4
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• pp.337-340
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• 2007

Pseudomonas syringae Pv. syringae is a causal agent of bacterial blossom blight of kiwifruit in Korea. Eleven strains of the pathogen were isolated from different kiwifruit orchards in Korea and the plasmid profiles were obtained by pulsed-field gel electrophoresis. They could be clustered into six groups according to the number and size of plasmids. The number of plasmids per strain and size of these plasmids ranged from 0 to 4 and from 22 to 160 kb, respectively. Among them, four strains belonging to Group III which harbored two plasmids were resistant to copper sulfate. Southern blot hybridization of the plasmid DNA indicated that the copper resistance determinant was carried on a 48 kb plasmid.

• 한국태양에너지학회:학술대회논문집
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• 2011.04a
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• pp.36-41
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• 2011

BIPV system that can alternate building envelope by making materials of PV module should be considered in initial design step for applying PV system efficiently in office building. Mean while, area of the building skin also increases as the number of floors increases, but the valid area that can apply BIPV system in effect decreases relatively. Despite of this weak point, installing BIPV system is still being evaluated as the only measure left that can reduce electronic energy consumption in the building. Therefore, the impact on building energy consumption according to the increase of the number of floors when BIPV system is applied in the building was analyzed. And it will be used as basic information for application of BIPV in office building. Conomic about application of BIPV is interpreted to be secured within the 10 story high. Forover the 11 floors, the methods of increasing the contribution ratio produced by BIPV system through the optimization of install angle and increase in install area of south, high efficiency should be considered. The ways to reduce basic load by integrated design with another renewable energy besides BIPV should be found. Later, the study on the total building energy comsumption with PV generation according to the various type of the basic load and ratio of the width and depth will be performed based on this study.

• Journal of the Microelectronics and Packaging Society
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• v.27 no.4
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• pp.55-60
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• 2020

The PERC photovoltaic (PV) modules installed in PV power plant are still reports potential-induced degradation (PID) degradation due to high voltage potential differences. This is because Na+ ions in the cover glass of PV modules go through the encapsulant (EVA) and transferred to the surface of solar cells. As positive charges are accumulated at the ARC (SiOx/SiNx) interface where many defects are distributed, shunt-resistance (Rsh) is reduced. As a result, the leakage current is increased, and decrease in solar cell's power output. In this study, to prevent of this phenomenon, a Moth-eye nanostructure was deposited on the rear surface of an optical film using Nano-Imprint Lithography method, and a solar mini-module was constructed by inserting it between the cover glass and the EVA. To analyze the PID phenomenon, a cell-level PID acceleration test based on IEC 62804-1 standard was conducted. Also analyzed power output (Pmax), efficiency, and shunt resistance through Light I-V and Dark I-V. As a result, conventional solar cells were decreased by 6.3% from the initial efficiency of 19.76%, but the improved solar cells with the Moth-eye nanostructured optical film only decreased 0.6%, thereby preventing the PID phenomenon. As of Moth-eye nanostructured optical film, the transmittance was improved by 4%, and the solar module output was improved by 2.5%.

• Journal of Power Electronics
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• v.10 no.4
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• pp.335-341
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• 2010

In this paper, an interleaved soft switching boost converter for a Photovoltaic Power Conditioning System (PV-PCS) with high efficiency is proposed. In order to raise the efficiency of the proposed converter, a 2-phase interleaved boost converter integrated with soft switching cells is used. All of the switching devices in the proposed converter achieve zero current switching (ZCS) or zero voltage switching (ZVS). Thus, the proposed circuit has a high efficiency characteristic due to low switching losses. To analyze the power losses of the proposed converter, two experimental sets have been built. One consists of normal devices (MOSFETs, Fast Recovery (FR) diodes) and the other consists of advanced power devices (CoolMOSs, SiC-Schottky Barrier Diodes (SBDs)). To verify the validity of the proposed topology, theoretical analysis and experimental results are presented.

• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.62.2-62.2
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• 2011

To guarantee 20-25 years to the lifetime of the PV modules without failure, reliability test of the module is very important. Field-aged test of the outdoor environment is required. However, due to time constraints, accelerated testing is required to predict the lifetime of PV modules and find causes of failure. Failure is caused by many complex phenomena. In this study, we experimented two accelerated tests about corrosion and fatigue, respectively. First, temperature cycling test for fatigue were tested and Coffin-Manson equation was analyzed. Second, damp heat test for corrosion were tested and Eyring equation were analyzed. Finally, using two-mode failure model, we suggest a new lifetime model that analyze the phenomenon by combining two kinds of data.

• JSTS:Journal of Semiconductor Technology and Science
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• v.15 no.5
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• pp.577-584
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• 2015

A photovoltaic (PV) system generates electricity by installing a solar energy array; therefore, the photovoltaic system can be easily exposed to external factors, which include environmental factors such as temperature, humidity, and radiation. These factors-as well as shading, in particular-lead to power degradation. When there is an output loss in the solar cell of a PV module package, the output loss is partly controlled by the bypass diode. As solar cells become highly efficient, the characteristics of series resistance and parallel resistance improve, and the characteristics of reverse voltage change. A bypass diode is connected in parallel to the string that is connected in series to the PV module. Ideally, the bypass diode operates when the voltage is -0.6[V] around. This study examines the bypass diode operating time for different types of crystalline solar cells. It compares the reverse voltage characteristics between the single solar cell and polycrystalline solar cell. Special modules were produced for the experiment. The shading rate of the solar cell in the specially made solar energy module was raised by 5% each time to confirm that the bypass diode was operating. The operation of the bypass diode is affected not only by the reverse voltage but also by the forward bias. This tendency was verified as the number of strings increased.

• Proceedings of the KIPE Conference
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• 2006.06a
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• pp.529-531
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• 2006

The Photovoltaic(PV) generation system is a promising source of energy for the future. Since the need for renewable energy has been increased, the research of PV generation system has also been progressed. The main subject of this paper is about making the more useful real-time monitoring program to get and save the data from photovoltaic generation system of 30kW grid-connected. Therefore, it uses LabView for this real-time monitoring program.

• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.1173-1174
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• 2006

The Photovoltaic(PV) generation system is a promising source of energy for the future. Since the need for renewable energy has been increased, the research of PV generation system has also been progressed. The main subject of this paper is about making the more useful real-time monitoring program to get and save the data from photovoltaic generation system of 30kW grid-connected. Therefore, it uses LabView for this real-time monitoring program.