• Journal of Electrochemical Science and Technology
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• 제7권3호
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• pp.218-227
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• 2016

The light harvesting efficiency is counted as an important factor in the power conversion efficiency of DSSCs. There are two measures to improve this parameter, including enhancing the dye-loading capacity and increasing the light trapping in the photoanode structure. In this paper, these tasks are addressed by introducing a macro-porous silicon (PSi) substrate as photoanode. The effects of the novel photoanode structure on the DSSC performance have been investigated by using energy dispersive X-ray spectroscopy, photocurrent-voltage, UV-visible spectroscopy, reflectance spectroscopy, and electrochemical impedance spectroscopy measurements. The results indicated that bigger porosity percentage of the PSi structure improved the both anti-reflective/light-trapping and dye-loading capacity properties. PSi based DSSCs own higher power conversion efficiency due to its remarkable higher photocurrent, open circuit voltage, and fill factor. Percent porosity of 64%, PSi(III), resulted in nearly 50 percent increment in power conversion efficiency compared with conventional DSSC. This paper showed that PSi can be a good candidate for the improvement of light harvesting efficiency in DSSCs. Furthermore, this study can be considered a valuable reference for more investigations in the design of multifunctional devices which will profit from integrated on-chip solar power.

• Current Photovoltaic Research
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• 제10권3호
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• pp.73-76
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• 2022

BIPV (Building Integrated Photovoltaic) supplemented the minimum area problem required when installing existing solar modules. However, in order to apply it to buildings, research was needed to increase the aesthetics of solar modules and use them as a design. Accordingly, modules with color applied to the entire surface of the photovoltaic module were being developed, but there was a disadvantage of low power. Therefore, by dividing and bonding the cell strips, it was possible to improve the output power by applying a shingled technology in which other divided cells overlap in a busbar region where light couldn't be received. Shingled technology was advantageous for color modules because the front busbar part that degrades aesthetics was removed. In this research, four color shingled solar modules (Green, Yellow, Blue, Gray) were manufactured and power degradation was analyzed by measuring transmittance and reflectance. Gray color had 80.83% transmittance, which was 31.31% higher than Yellow, resulting in a power difference of 4.45 W.

• Current Photovoltaic Research
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• 제3권4호
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• pp.121-125
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• 2015

BIPV system is one of the best ways to harness PV module. The BIPV system not only produces electricity, but also acts as a building envelope. Thus, it has the strong point of increasing the economical efficiency by applying the PV modules to the buildings. Bifacial solar cells can convert solar energy to electrical energy from both sides of the module. In addition, it is designed as 3 busbar layout which is the same with ordinary mono-facial soalr cells. Therefore, many of the module manufacturers can easily produce the bifacial solar cells without changing their manufacturing equipment. Moreover, bifacial BIPV system has much potential in building application by utilizing glass to glass structure. However, the performance of bifacial solar cells depends on a variety of factors, ranging from the back surface to surrounding conditions. Therefore, in order to apply bifacial solar cells to buildings, an analysis of bifacial PV module performance should be carried out that includes a consideration of various design elements, and reflects a wide range of installation conditions. As a result it found that the white insulation reflector type can improve the performance of the bifacial BIPV system by 16%, compared to the black insulation reflector type. The performance of the bifacial BIPV was also shown to be influenced by inclination angle, due to changes in both the amount of radiation captured on the front face and the radiation transmitted to the rear face through the transparent space. In this study is limited design condition and installation condition. Accordingly follow-up researches in this part need to be conducted.

• 전기학회논문지
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• 제57권11호
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• pp.1994-2000
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• 2008

The output power of photovoltaic(PV) generation system is strongly affected by weather conditions. To make up for the defect of solar energy, energy storages such as battery and electrolyzer are usually integrated with photovoltaic cell. This paper focuses on the way to store energy surplus with battery and electrolyzer and to provide energy with battery. Photovoltaic generation system is modeled with PV cell, DC/DC converter, DC/AC inverter, battery and electrolyzer. The operation algorithm to regulate PV output power with battery and electrolyzer is suggested. The simulation results show that battery and electrolyzer effectively cooperate with each other to compensate the fluctuation of PV generation system.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.460-460
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• 2014

Organic photovoltaic cells (OPV) have been extensively studied due to their unique properties such as flexibility, light-weight, easy processability, cost-effectiveness, and being environmental friendly. These advantages make them an attractive candidate for application in various novel fields and promising development with new features. Photovoltaic cell-integrated textiles have greatly attractive features as a power source for the smart textile solutions, and OPV is most ideal form factor due to advantage of flexibility. In this study, we develop a textile-based OPV through various experimental methods and we suggest the direction for the design of the photovoltaic textile. We used a textile electrode and tried to various layouts for textile-based OPV. Finally, we determined the contact area by using Hertzian theory for the calculation of power conversion efficiency (PCE). Based on the results of calculation, the short circuit current density, Isc, was $13.11mA/cm^2$ under AM 1.5condition and the PCE was around 2.5%.

• 한국태양에너지학회 논문집
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• 제23권1호
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• pp.1-8
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• 2003

Various efforts to combine new high-tech materials with solar system have been progressed nowadays in order to improve the performance of the existing passive solar system. TIM(Transparent Insulation Material) replacing the conventional outer building envelope glazing as well as the wall is good example for this trend. TI integrated wall is a thermal mass wall with a special shaped TIM instead of using typical envelope materials The tested TIM type is a small(diameter 4mm and thickness 50mm) capillary tube of Okalux model and cement brick(density 1500kg/m3). The purpose of this study was to analyze the thermal performance through the actual measurements performed in a test cell. This study was carried out to justify the following issues. 1) the impact of Tl-wall over the temperature variations 2) the impact of mass wall surface absorptance over the transient thermal behavior and 3) the impact of thermal mass wall thickness over the temperature variations. Finally, as results indicated that the peak time of room temperature was shifted about one hour early when absorptance of thermal mass wall changed from 60% to 95% for the 190mm thickness thermal mass wall test case. the temperature difference of both surfaces of thermal mass wall surface showed about $23^{\circ}C$ during a day of March for the 380mm thickness thermal mass wall case. However, the thermal mass wall was over-heated by outside temperature and solar radiation in a day of May the temperature difference of both surfaces of thermal mass wall surface was indicated $10^{\circ}C$ and inside temperature was observed more than average 22C.

• KIEAE Journal
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• 제4권3호
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• pp.113-119
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• 2004

As Building Integrated Photovoltaic(BIPV) system replaces the conventional building finishing materials with PV modules, two function of electricity generation and building envelope can be expected. Therefore BIPV can be a good alternative technology for the 21 century environment-friendly buildings. The objective of this paper is to develope BIPV modules for a commercial buildings of which structure is mainly light-weight, curtain wall system. Two types of module are developed for a opaque part and a transparent part of building envelope. Current technology level and market status of Korea determines the configuration of developed BIPV modules. Architectural considerations for the integration of PV module to building envelope such as building structure, construction type, safety, regulation, maintenance etc. have been carefully reflected from the early stage of BIPV module design. Especially the survey result of current building envelope materials determines the size of unit BIPV modules and a unique cladding method for PV module installation is developed. Trial product of BIPV modules and cladding hardwares are manufactured and sample construction details for a demonstration building are proposed.

• 마이크로전자및패키징학회지
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• 제23권2호
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• pp.65-71
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• 2016

본 연구에서는 나노 입자 적층 시스템(Nano Particle Deposition System, NPDS)을 이용하여 전기변색소자의 작동 전극을 적층하고 또한 염료 감응 태양전지의 반도체 층으로 사용되는 $TiO_2$층 및 전기변색소자의 이온 저장 층으로 사용되는 Antimony Tin Oxide(ATO) 층을 제작하였다. NPDS는 상온 건식 분말 적층법으로 노즐을 통하여 초음속으로 가속된 분말의 높은 에너지를 이용하여 기판에 적층하는 새로운 개념의 건식 적층 방법이다. 본 연구에서 코팅된 물질의 두께는 전기변색소자의 투과율에 영향을 끼치는데, 이는 표면 프로파일 측정법(surface profiling method)으로 측정하였으며, 적층된 $TiO_2$와 ATO 및 복합 층의 미세 구조를 확인하기 위해 SEM을 이용한 분석을 진행하였다. 한편 염료 감응 태양전지의 광 변환 효율은 솔라 시뮬레이터로 분석하였다. 또한 UV-visible spectrometer와 power source를 이용하여 630 nm 대역에서 전기 변색 소자가 갖는 투과도 변화와 낮은 전압에서의 작동 및 변색 횟수를 측정하였으며, 결과적으로 상기 과정을 거쳐 제작되고, 측정된 염료 감응 태양전지 - 전기 변색 통합 구조 소자를 자체 제작한 에너지 하베스팅 시스템과 연결하여 통합 구조 소자 내 태양전지의 전압 발생을 통해 자체 구동이 가능한 전기 변색 소자 시스템 제작에 성공하였다. NPDS를 통해 제작된 변색 소자의 경우, 최대 49%의 투과도 변화와 500회 작동에서 C-V curve를 유지함을 측정하여 성능과 내구성을 입증하였고, 통합 소자 내 태양 전지의 광 변환 효율은 최대 2.55%로 측정되었으며, 통합 소자 내 변색 소자의 경우 최대 26%의 투과도 변화를 보였다.

• 한국산학기술학회논문지
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• 제19권1호
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• pp.63-68
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• 2018

본 논문은 이산화탄소 고정 과정이 포함된 인공 광합성 과정을 모사하기 위하여 지구상에 흔히 존재하는 촉매 재료를 이용해 개발한 광화학 반응 시스템(인공나뭇잎)과 시스템 에너지 포집 및 변환 능력에 대한 성능을 조사하기 위한 기초 연구 결과를 제시한다. 본 연구에서 개발한 시스템은 태양광 전지의 전면부에 산화코발트를 도핑 하여 물의 전기분해로 인한 산소 발생이 태양전지 표면에서 직접 발생하도록 하였고, 후면 기판 표면에는 이산화탄소 변환 반응을 위한 효율적인 촉매로 $MoS_2$를 도핑 하여, 전선이 없는 구조로 구성하였다. 직접 태양광 연료 변환 시스템은 약4.5%로 이산화탄소를 일산화탄소와 수소로 변환하여 지속 가능한 연료(합성가스)의 형태로 생산하며, 이는 음극에서 촉매 변환 효율이 75%이상이 될 수 있음을 의미한다. 본 연구는 물의 광분해뿐만 아니라 태양광에 의해 유도된 이산화탄소 전환 과정을 하나의 시스템에서 동시에 실현하여 자연적 광합성 과정을 좀 더 성공적으로 모사할 수 있는 시스템 개발에 기여하였다.

• 한국항공우주학회지
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• 제40권11호
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• pp.940-947
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• 2012

연구대상으로 삼은 중형 전기추진 무인기는 무게 18.5 kg, 날개 길이 6.4 m급의 저속 장기체공형으로 태양전지, 연료전지, 배터리를 전력원으로 사용한다. 이륙시간에 따라 태양전지의 에너지 총량이 달라지므로 체공을 최대화하기 위한 최적의 이륙시간을 선정해야 한다. 이를 위해 전압매칭을 통해 각 전력원을 선정하여 모델링을 수행하였으며 단품 성능시험을 통해 검증 후 시뮬레이션을 수행하였다. 이륙시간이 오전 6시, 오전 2시일 때 각각 최대 37.5시간, 최소 27.6시간동안 전력공급이 가능하였다. 배터리 SOC의 사용범위를 25~80%로 제한하도록 연료전지의 작동을 제어할 경우 각각 0.31시간, 0.63시간동안 더 전력공급이 가능하며 각 전력원은 최적 운전점에서 작동함을 확인하였다.