• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2009년도 하계학술대회 논문집
• /
• pp.440-440
• /
• 2009

Semiconductor nanowires offer exciting possibilities as components of solar cells and have already found applications as active elements in organic, dye-sensitized, quantum-dot sensitized, liquid-junction, and inorganic solid-state devices. Among many semiconductors, silicon is by far the dominant material used for worldwide photovoltaic energy conversion and solar cell manufacture. For silicon wire to be used for solar device, well aligned wire arrays need to be fabricated vertically or horizontally. Macroscopic silicon wire arrays suitable for photovoltaic applications have been commonly grown by the vapor-liquid-solid (VLS) process using metal catalysts such as Au, Ni, Pt, Cu. In the case, the impurity issues inside wire originated from metal catalyst are inevitable, leading to lowering the efficiency of solar cell. To escape from the problem, the wires of purity of wafer are the best for high efficiency of photovoltaic device. The fabrication of wire arrays by the electrochemical etching of silicon wafer with photolithography can solve the contamination of metal catalyst. In this presentation, we introduce silicon wire arrays by electrochemical etching method and then fabrication methods of radial p-n junction wire array solar cell and the various merits compared with conventional silicon solar cells.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
• /
• pp.298-298
• /
• 2013

Finding renewable and clean energy resources is essential research to solve global warming and depletion of fossil fuels in modern society. Recently, complex harvesting of energy from multiple sources is available in our living environments using a single device has become highly desirable, representing a new trend in energy technologies. We report that when simultaneously driving the fusion and composite cells of two or more types, it is possible to make an affect the other cells to obtain a greater synergistic effect. To understand the coupling effect of photovoltaic and piezoelectric device, we fabricate the serially integrated hybrid cell (s-HC) based on organic solar cell (OSC) and piezoelectric nanogenerator (PNG). The size of increased voltage peaks when OSC and PNG are working on is larger than the case when only PNG is working. This voltage difference is the Voc change of OSC, not the voltage change of PNG and current density difference between these two cases is manifested more clearly. When the OSC and PNG are working in s-HC at the same time, piezoelectric potential (VPNG) is generated in ZnO and theoretical total voltage is sum of voltage of an OSC (VOSC) and VPNG. However, electrons from OSC are influenced by piezoelectric potential in ZnO and current loss of OSC in whole circuit decreases. As a result, VOSC increases temporarily. Current shows the similar behavior. PNG acts a resistance in the whole circuit and current loss occurs when the electrons from OSC pass through the PNG. But piezoelectric potential recover current loss and decrease the resistance of PNG. Our PNG can maintain piezoelectric potential when the strain is held owing to the LDH layer while general PNG cannot maintain piezoelectric potential. During the section that strain is held, voltage enhancement effect is maintained and same effect appeared even turn off the light. Actually at this time, electrons in ZnO nanosheets move to LDH and trapped by the positive charges in this layer. After this strain is held, piezoelectric potential of ZnO nanosheets is disappeared but potential difference which is developed by negative charge dominant LDH layer is remained. This potential acts similar role like piezoelectric potential in ZnO. Electrons from the OSC also are influenced by this potential and the more current flows.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
• /
• pp.157-158
• /
• 2013

Organic solar cell was fabricated using one-pot deposition of a mixture of NiO nanoparticles, P3HT and PCBM. In the presence of NiO, the photovoltaic performance was slightly increased comparing to that of the device without NiO. When $TiO_2$ thin films with a thickness of 2~3 nm was prepared on NiO nanoparticles using atomic layer deposition, the power conversion efficiency was increased by a factor 2.5 with respect to that with bare NiO. Moreover, breakdown voltage of the film consisting of NiO, P3HT, and PCBM on indium tin oxide was increased by more than 1 V in the presence of $TiO_2$-shell on NiO nanoparticles. It is evidenced that S atoms of P3HT can be oxidized on NiO surfaces, and $TiO_2$-shell on NiO nanoparticles. It is evidenced that S atoms of P3HT can be oxidzed on NiO surfaces, and $TiO_2$ shell heavily reduced oxidation of S at oxide/P3HT interfaces. Oxidized S atoms can most likely act as carrier generation sites and recombination centers within the depletion region, decreasing breakdown voltage and performance of organic solar cells. Our result shows that fabrication of various core-shell nanostruecutres of oxides by atomic layer deposition with controlled film thickness can be of potential importance for fabricating highly efficient organic solar cells.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
• /
• pp.221-221
• /
• 2012

Small-molecule organic photovoltaic cells have recently attracted growing attention due to their potential for the low-cost fabrication of flexible and lightweight solar modules. The PVP/Ag nanoparticles were synthesized by the reaction of poly vinylpyrrolidone (PVP) and silver nitrate at $150^{\circ}C$. In the reaction, the size of the nanoparticles was controlled by relative mole fractions between PVP and Ag. The PVP/Ag nanoparticles with various sizes were then spin coated on the patterned ITO glass prior to the deposition of the PEDOT:PSS hole transport layer. The scattering of the incident light caused by these incorporated nanoparticles resulted in an increase in the path length of the light through the active layer and hence the enhancement of the light absorption. This scattering effect increased as the size of the nanoparticles increased, but it was offset by the decrease in total transmittance caused by the non-transparent nanoparticles. As a result, the maximum power conversion efficiency, 0.96% which was the value enhanced by 14% compared to the cell without incorporation of nanoparticles, was obtained when the mole fraction of PVP:Ag was 24:1 and the size of the nanoparticles was 20~40 nm.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2010년도 춘계학술대회 초록집
• /
• pp.73.2-73.2
• /
• 2010

Polymer solar cells (PSCs) have attracted considerable academic and commercial interest because of their unique advantages, such as the facile manufacture of low cost, flexibility, lightweight, and solution processibility. Recently, high-performance polymer solar cells made from a mixture of poly(2,7-carbazole) derivatives, PCDTBT, and [6,6]-phenyl C71 butyric acid methyl ester (PC70BM) have been reported, with maximum power conversion efficiency of 6.1%. In this work, we report new novel copolymers based on poly(2,7-carbazole) derivatives with a suite of electron-deficient moieties or electron-rich units. We systematically investigated the synthesis, thermal stability, as well as the optical and electrochemical properties of these polymers. Detailed synthetic scheme, optical, electrochemical, and photovoltaic properties of the copolymers will be presented.

• 한국자동차공학회논문집
• /
• 제22권6호
• /
• pp.89-95
• /
• 2014

This study presented the benefit of the pre-ventilation using solar sunroof with integrated photovoltaic. Recent year, auto-makers make an effort to enhance the fuel efficiency and moreover to clean the cabin passenger's health. Solar energy, one of the alternative energies, adapted in automotive air handling system, in order to pre-ventilation when vehicle parked under the sun in summer. The power generated by a prototype solar sunroof has been used to run blower in a air handing system. And the solar sunroof was installed in a vehicle, and evaluated to find out benefit of the pre-ventilation. The effect of reducing the cabin temperature about $3^{\circ}C{\sim}10^{\circ}C$ with 20 ~ 40W power generator from solar sunroof were obtained in the pre-ventilation test. This reduced thermal load can lead to the reduction of air-conditioning operation time than that of current car. Moreover, fuel economy may increase as a results of the short use of the air-conditioning time. Additionally, Total Volatile Organic Compounds in the cabin is reduced maximum 80% than that of the current vehicle.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
• /
• pp.469.1-469.1
• /
• 2014

일반적으로 유기전자소자의 제작에 있어서 Indium tin oxide (ITO)는 뛰어난 전기 광학적 특성을 바탕으로 가장 보편적으로 사용되는 투명전극이다. 특히 유기태양전지(Organic Photovoltaic, OPV)나 유기발광디스플레이(Organic Light Emitting Device)는 ITO 위에 PEDOT:PSS 층을 형성하여 HOMO, LUMO를 조절하고 효율을 향상시키는 역할을 수행하고 있다. 특히 ITO 위의 PEDOT:PSS는 사용되는 용제의 종류나 첨가제 등에 따라 특성이 크게 영향을 받는다. 이때 PEDOT:PSS는 일반적으로 강산성을 띄게 됨으로써 유기전자소자의 장시간 안정성을 저하시키는 원인으로 작용한다. 본 연구에서는 각각 다른 pH level을 가진 PEDOT:PSS의 시간 경과에 따라 투과도와 면저항을 측정하고 각각의 PEDOT을 사용하여 유기태양전지 소자를 제작하였다. 소자제작 30일 경과 후 소자의 효율이 감소하기는 하였으나 그 변화가 일반적으로 사용되는 pH 2의 감소보다 현저히 적었음을 알 수 있다. 이러한 pH 변화가 이를 적용한 투명전극 필름의 전기 광학적 특성인 투과도 면저항 등에는 영항을 거의 미치지 않으면서도 OPV의 효율 변화에는 큰 차이를 보이는 것을 알 수 있다.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
• /
• pp.275.1-275.1
• /
• 2014

The effects of the interfacial buffer layer and temperature on the organic bulk heterojunction (BHJ) nanostructures of copper phthalocyanine (CuPc) and fullerene (C60) systems were investigated using real time in-situ x-ray scattering. In the CuPc:C60 BHJ structures, standing-on configured ${\gamma}$-CuPc phase was formed by co-deposition of CuPc and C60. Once formed ${\gamma}$-phase was thermally stable during the annealing upon $180^{\circ}C$. Meanwhile, the insertion of CuI buffer layer prior to deposition of the CuPc:C60 BHJ layer induced lying-down configured CuPc crystals in the BHJ layer. The lying CuPc peak intensity and the lattice parameter were increased by the thermal annealing. This increment of the intensity seemed to be related to the strain at the interface between CuPc:C60 and CuI, which was proportional to the enhancement of the power conversion efficiency of the device.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2009년도 추계학술대회 논문집
• /
• pp.350-354
• /
• 2009

In this work, polymer - inorganic composites have prepared using polymer such as polyethylene glycol (PEG)/poly (methyl methacrylate, PMMA) and inorganic nanofillers materials such as TiO2 nanotubes (TiNTs)/carbon nanotubes (CNTs). The extensive structural, morphological and ionic properties revealed that the high surface area and tubular feature of nanofillers improved the interaction and cross-linking to polymer matrix which is significantly enhanced the ionic conductivity and electrical properties of composite electrolytes. Comparably high conversion efficiency ~4.5% has been observed by using the newly prepared PEG-TiNTs composite solid electrolyte as compared with PMMA-CNTs electrolyte based DSSCs (~3%). The detailed comparative properties would be discussed in term of their structural, morphology, ionic and photovoltaic properties.

• Bulletin of the Korean Chemical Society
• /
• 제32권3호
• /
• pp.1067-1070
• /
• 2011

We have demonstrated that solution-based fabrication of NiO films as HTL can be used for the construction of IOSCs. Type of solvent of NiO-solution, and annealing procedure of the active layers were optimized for obtaining a PCE of 3% of IOSC. The photovoltaic performance of NiO-based device is comparable to that of the same type of solar cell using PEDT:PSS instead of NiO. These solution-based processes can be a promising method for a mass production OSCs under ambient condition.