• Ceramist
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• v.21 no.2
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• pp.75-82
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• 2018

In the photovoltaics (PV) industry, there were many efforts to reduce the cost of production with high efficiency. The single most important cost factor in silicon technology is the wafer, accounting presently for ~35% of the module cost. it was already shown that the solar cell efficiency can be maintained up to the thickness range of $40-60{\mu}m$. The direct production of ultra-thin silicon wafer is very attractive and numerous different techniques, such as electrochemical process, ion implantation, and epitaxial growth, have been proposed and developed in many academic and industrial laboratories.

• 한국태양에너지학회:학술대회논문집
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• 2011.04a
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• pp.15-16
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• 2011

In this paper, I suggested the energy flexibility for photovoltaic energy. The cost for PV is surely high. But renewable energy is an one of the key solution for next energy resource. The latest technology needs more electricity. So many people are carrying more mobile charge in their batteries. Looking at the poor country people and nation, it is necessary to supply and share the advanced energy resources like photo voltaic. So in this open seminary I want to share the idea for this theme. The detail discussion will be shown in the following paper.

• Proceedings of the KIPE Conference
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• 2005.07a
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• pp.68-70
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• 2005

The arrangement technique of solar cell and module is accomplished quickly with development of power semiconduc-tors. It reached to a practical cost linearly. Photovoltaic power system increases constantly. There are 3kWtracking photovoltaic system and fixed photovoltaic system in Chosun University. This paper compares operating characteristics of the fixed photovoltaic system and the tracking photovoltaic system with shows the efficiency.

• Proceedings of the KIPE Conference
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• 2013.07a
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• pp.66-67
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• 2013

태양광전지는 태양광 에너지를 전기에너지의 형태로 변환한다. 태양광전지는 부하조건에 따라 전류원 및 전압원의 특성을 모두 갖는 I-V 특성곡선을 나타낸다. 같은 회사에서 제조한 동일한 모델의 태양광전지라 하더라도 특성에 조금씩 편차가 발생한다. 태양광전지를 직렬접속하여 대규모의 태양광어레이를 구성하는 경우, 각 태양광전지의 특성편차는 전체 태양광어레이의 전력생산능력을 감소시키게 되므로 같은 특성을 갖는 태양광전지를 구별하여 어레이를 제작할 필요가 있다. 본 논문에서는 이러한 태양광전지의 특성을 자동적으로 측정 분석하여 LabVIEW GUI화면을 통하여 결과를 출력하는 태양광전지 성능 분석기를 개발한다.

• Transactions on Electrical and Electronic Materials
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• v.17 no.1
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• pp.21-24
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• 2016

A junction box used in a 3 kW photovoltaic power generation system plays a role in collecting and supplying the direct current voltage produced by photovoltaic modules to an inverter. It is also used for facilitating maintenance checks and protecting the module and inverter by keeping the voltage constant. As for the junction box, using it in a parallel connection creates a difference between the setup modules. In order to compensate, an inverse voltage diode is used. But the high-power created through the solar generator can be delivered to the inverter through the inverter regularly. Therefore, a component can break down due to excess heat. And consequently short circuits and electric leakage occurs. In this study, using a junction box that enabled the bypass of high electric power, it was possible to reduce heat generation by approximately 35℃ when compared to a standard junction box.

• Journal of the Semiconductor & Display Technology
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• v.21 no.4
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• pp.110-115
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• 2022

Accurate current-voltage modeling of solar cell systems plays an important role in power prediction. Solar cells have nonlinear characteristics that are sensitive to environmental conditions such as temperature and irradiance. In this paper, the output characteristics of photovoltaic module are accurately predicted by combining the artificial neural network and physical model. In order to estimate the performance of PV module under varying environments, the artificial neural network model is trained with randomly generated temperature and irradiance data. With the use of proposed model, the current-voltage and power-voltage characteristics under real environments can be predicted with high accuracy.

• Korean Journal of Materials Research
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• v.25 no.4
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• pp.196-201
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• 2015

This paper presents the impact of partial shading on $CuIn_xGa_{(1-x)}Se_2(CIGS)$ photovoltaic(PV) modules with bypass diodes. When the CIGS PV modules were partially shaded, the modules were under conditions of partial reverse bias. We investigated the characterization of the bypass diode and solar cell properties of the CIGS PV modules when these was partially shaded, comparing the results with those for a crystalline silicon module. In crystalline silicon modules, the bypass diode was operated at a partial shade modules of 1.67 % shading. This protected the crystalline silicon module from hot spot damage. In CIGS thin film modules, on the other hand, the bypass diode was not operated before 20 % shading. This caused damage because of hotspots, which occurred as wormlike defects in the CIGS thin film module. Moreover, the bypass diode adapted to the CIGS thin film module was operated fully at 60% shading, while the CIGS thin film module was not operated under these conditions. It is known that the bypass diode adapted to the CIGS thin film module operated more slowly than that of the crystalline silicon module; this bypass diode also failed to protect the module from damage. This was because of the reverse saturation current of the CIGS thin film, $1.99{\times}10^{-5}A/cm^2$, which was higher than that of crystalline silicon, $8.11{\times}10^{-7}A/cm^2$.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.10
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• pp.4733-4739
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• 2012

While traditional two-axis tracking systems with double sensors had been using two sensors to control azimuth and elevation angle of the sun so that a solar cell module would make a normal line with the sun, this paper proposed a new two-axis system that can achieve the same performance with only one sensor in it. It is Two-axis tracking system that control azimuth and elevation to control to be reduced for solar cell module as proposed tracking system uses 1 sensors and the sun always forms normal. Two-axis tracking system of one sensor method that propose in paper that could reduce electric power consumption and sees than fixed type preventing action and the most efficient driving and needless drive could confirm that generation efficiency of about 23 [%] increases. To heighten efficiency of solar cell doing to receive more sunlights chasing the sun, done tracking device have proceeded a lot of studies in large size way. Therefore, is expected that will do big part in the sun tracking supply through utility study about persistent generation efficiency constructing monitoring system of the sun tracking of this paper.

• Proceedings of the Materials Research Society of Korea Conference
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• 2011.10a
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• pp.35.1-35.1
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• 2011

New photovoltaic (PV) materials and manufacturing approaches are needed for meeting the demand for lower-cost solar cells. The prototypal thin-film photovoltaic absorbers (CdTe and $Cu(In,Ga)Se_2$) can achieve solar conversion efficiencies of up to 20% and are now commercially available, but the presence of toxic (Cd,Se) and expensive elemental components (In, Te) is a real issue as the demand for photovoltaics rapidly increases. To overcome these limitations, there has been substantial interest in developing viable alternative materials, such as $Cu_2ZnSnS_4$ (CZTS) is an emerging solar absorber that is structurally similar to CIGS, but contains only earth abundant, non-toxic elements and has a near optimal direct band gap energy of 1.4~1.6 ev and a large absorption coefficient of ${\sim}10^4\;cm^{-1}$. The CZTS absorber layers are grown and investigated by various fabrication methods, such as thermal evaporation, e-beam evaporation with a post sulfurization, sputtering, non-vacuum sol-gel, pulsed laser, spray-pyrolysis method and electrodeposition technique. In the present work, we report an alternative method for large area deposition of CZTS thin films that is potentially high throughput and inexpensive when used to produce monolithically integrated solar panel modules. Specifically, we have developed an aqueous chemical approach based on chemical bath deposition (CBD) with a subsequent sulfurization heat treatment. Samples produced by our method were analyzed by scanning electron microscopy, X-ray diffraction, transmission electron microscopy, absorbance and photoluminescence. The results show that this inexpensive and relatively benign process produces thin films of CZTS exhibiting uniform composition, kesterite crystal structure, and good optical properties. A preliminary solar cell device was fabricated to demonstrate rectifying and photovoltaic behavior.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2004.10a
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• pp.65-67
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• 2004

During initial interactions of bacteria with their host plants, most plants recognize the bacterial infections and repel the pathogen by plant defense mechanism. The most active plant defense mechanism is the hypersensitive response (HR) which is the localized induced cell death in the plant at the site of infection by a pathogen. A primary locus induced in gram-negative phytopathogenic bacteria during this initial interaction is the Hrp locus. The Hrp locus is composed of a cluster of genes that encodes the bacteral Type 111 machinery that is involved in the secretion and translocation of effector proteins to the plant cell. DNA sequence analysis of hrp gene in phytopathogenic bacteria has revealed a Hrp pathogenicity is]and (PAI) with a tripartite mosaic structure. For many gram-negative pathogenic bacteria, colonization of the host's tissue depends on the type III protein secretion system (TTSS) which secrets and translocates effector proteins into the host cell. Effectors can be divided into several groups including broad host range effectors, host specific effectors, disease specific effectors, and effectors inhibit host defenses. The role of effectors carrying LRR domain in plant resistance is very elusive since most known plant resistance gene carry LRR domain. Host specific effectors such as several avr gene products are involved in the determination of the host specificity. Almost all the phytopathogenic Xanthomonas spp. carry avrBs1, avrBs2, and avrBs3 homologs. Some strains of X. oryzae pv. oryzae carry more than 10 copies of avrBs3 homologs. However, the functions of all those avr genes in host specificity are not characterized well.;