Silver Nanowire Embedded in P3HT:PCBM for High-Efficiency Hybrid Photovoltaic Device Applications

Kim, Chul-Hyun,Cha, Sang-Ho,Kim, Sung Chul,Song, Myungkwan,Lee, Jaebeom,Shin, Won Suk,Moon, Sang-Jin,Bahng, Joong Hwan,Kotov, Nicholas A.,Jin, Sung-Ho American Chemical Society 2011 ACS NANO Vol.5 No.4

<P>A systematic approach has been followed in the development of a high-efficiency hybrid photovoltaic device that has a combination of poly(3-hexylthiophene) (P3HT), [6,6]-phenyl C61-butyric acid methyl ester (PCBM), and silver nanowires (Ag NWs) in the active layer using the bulk heterojunction concept. The active layer is modified by utilizing a binary solvent system for blending. In addition, the solvent evaporation process after spin-coating is changed and an Ag NWs is incorporated to improve the performance of the hybrid photovoltaic device. Hybrid photovoltaic devices were fabricated by using a 1:0.7 weight ratio of P3HT to PCBM in a 1:1 weight ratio of <I>o</I>-dichlorobenzene and chloroform solvent mixture, in the presence and absence of 20 wt % of Ag NWs. We also compared the photovoltaic performance of Ag NWs embedded in P3HT:PCBM to that of silver nanoparticles (Ag NPs). Atomic force microscopy, scanning electron microscopy, transmittance electron microscopy, UV−visible absorption, incident photon-to-current conversion efficiency, and time-of-flight measurements are performed in order to characterize the hybrid photovoltaic devices. The optimal hybrid photovoltaic device composed of Ag NWs generated in this effort exhibits a power conversion efficiency of 3.91%, measured by using an AM 1.5G solar simulator at 100 mW/cm<SUP>2</SUP> light illumination intensity.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/ancac3/2011/ancac3.2011.5.issue-4/nn200469d/production/images/medium/nn-2011-00469d_0009.gif'></P>

Adapative Load Anti-islanding Method of Large Distributed Photovoltaic Power Grid

Xiaoyu Chen,Jianyong Zheng,Jun Mei 보안공학연구지원센터 2016 International Journal of Grid and Distributed Comp Vol.9 No.8

A large number of distributed photovoltaic power grid, islanding problems become more prominent. This paper first analyzes some existing anti-islanding scheme, and analyzes its advantages and disadvantages. Then, this paper proposes adaptive anti-islanding scheme by using the load, i.e. load automatic switching, changing the characteristics of the whole load, make the passive anti-islanding without dead-zone. Then using PSCAD simulation of the program, to verify the usefulness of the proposed scheme. To minimize the distributed photovoltaic power grid investment, saving the scheme relies on a new generation of distributed photovoltaic (pv) grid interface device. Then the paper introduces the overall structure and function of the device configuration, the device not only can solve the problem of area of backup protection, also save on investment, convenient for on-site equipment installation and maintenance, for the widespread promotion of distributed photovoltaic power grid to lay a solid foundation.

주택용 태양광발전설비 유지관리용 애플리케이션 개발

김재엽 대한건축학회지회연합회 2018 대한건축학회연합논문집 Vol.20 No.6

The purpose of this study is to develop an application that supports a user in the maintenance of small photovoltaic device. To this end, this study analyzed the maintenance status, related regulations and existing application contents in Korea. According to the analysis results, most users did not maintain device for themselves. In addition, the maintenance market has not been activated due to its low profitability. Regulations on the maintenance of photovoltaic device prescribed by the KESCO and Japanese counterpart were analyzed to establish the standards for photovoltaic device inspection, and an application was developed based on the existing applications and research results. In order to evaluate the completeness and satisfaction of the developed application, it surveyed 52 users and 22 experts. The survey results showed that the completeness was calculated to be 90 points, and the level of satisfaction was 93 points on a 100-point scale. Therefore, it is expected that the maintenance application developed in this study will be useful for users to maintain the photovoltaic device. 본 연구는 사용자 스스로 소형 태양광발전설비의 유지관리를 지원하는 애플리케이션을 개발하는 목적으로 시행되었다. 이를 위해 본 연구에서는 우리나라의 유지관리 현황, 관련 규정 및 기존 애플리케이션 내용을 분석하였다. 분석 결과 대부분의 사용자는 자체적으로 유지관리를 하지 않고 있었다. 또한, 수익성이 낮아 소형 태양광발전설비의 유지관리 시장은 활성화되지 않고 있다. 한국전기안전공사와 일본 태양광발전설비 유지관리 규정을 분석하여 태양광발전설비 검사 기준을 정하고, 분석한 내용을 바탕으로 애플리케이션을 개발했다. 개발 된 애플리케이션의 완성도와 만족도를 평가하기 위하여 52명의 사용자와 22명의 전문가를 대상으로 설문조사를 실시하였다. 설문 조사 결과 애플리케이션의 완성도는 100점 만점 중 90으로 나타났고, 만족도는 93점으로 나타났다. 본 연구에서 개발 된 태양광발전설비 유지관리 애플리케이션은 사용자 스스로 발전설비의 유지관리를 하는데 유용하게 사용될 것으로 기대된다.

냉각 시스템으로 Peltier 장치를 사용하여 태양 광 패널의 성능 분석

이드아함드파지 ( Ahmed Fawzy Eid ),홍성구 ( Hong Seong-gu ) 한국농공학회 2019 한국농공학회 학술대회초록집 Vol.2019 No.-

One of the main challenges for solar photovoltaic system is temperature rising of solar module, which causes to decrease maximum power voltage (Vmp) of panel. Furthermore, leads to decrease in electrical efficiency, maximum power (Pmax) of solar panel and will cause cells degradation and above lowering of life span expectancy of photovoltaic panels systems. To manage this issue, one of the important methods to improve the solar panel efficiency and keep it at a sufficient level is cooling. There are a lot of methods which are used to cool solar modules such as floating cooling system (FCC), photovoltaic/thermal (PVT) cooled by forced water circulation, solar panel with water immersion cooling technique and thermoelectric device as cooling systems called also Peltier effect device. In this study, two solar panels with different cooling devices were compared with a reference panel (model 3) with respect to its efficiency and performance. A new design of photovoltaic/thermoelectric cooler (PV-TEC) as a cooling system was attached with two fans and two heat sink as one unit, it fixed on the backside of the solar module to cool it from the back (model 2). Another method was a water film (model 1) to improve the electrical module efficiency. A 70 Watts small pump created a water film on the front side of the solar panel to remove the heat from the front. The first results of this study showed the temperatures were 35.5℃, 49 ℃ and 57 ℃ for model 1, model 2 and model 3 respectively. The maximum power voltages were 21.36V, 20.69V and 20.05V respectively. Short circuit currents were 5.31A, 5.36A and 5.37A respectively. The ideal output power from modules were 114W, 111W and 107.5W respectively with an improvement in electricity efficiency were 6% and 3.5% for model 1 and model 2 respectively .the cooling system by water film achieved a proper impact on electricity efficiency otherwise the capacity of the thermoelectric cooling unit was not enough to remove the heat from the back sheet of the solar module because of low thermal conductivity of Taddler layer.

Nanostructuring Methods for Enhancing Light Absorption Rate of Si-Based Photovoltaic Devices: A Review

김영범,홍순욱,배지웅,구봉준,장익황,조구영,차석원,Fritz B. Prinz 한국정밀공학회 2014 International Journal of Precision Engineering and Vol.1 No.1

In recent years, there has been growing consideration of renewable energy especially photovoltaic devices. A silicon (Si) based solar cell is the most popularly and frequently considered among the photovoltaic devices, but its bulk thickness issue lowers the performance and hinders widespread application due to the material cost. Also, this thick nature causes difference in length between minority carrier diffusion and sufficient light absorption. To mitigate the issues there have been many recent studies on Si photovoltaic devices adopting nanostructuring strategies to enhance the performance. Therefore, we report two different approaches on recent nanostructuring techniques for photovoltaic devices; bottom-up and top-down processes, which are composed of vapor-liquid-solid, solution-liquid-solid, reactive ion etching with Langmuir Blodgett and metal assisted chemical etching. Those fabrication processes enable the fabrication of nanostructures with a highly ordered and alignment structures leading to enhance the light absorption and have an appropriate thickness of Si substrate regressing Auger recombination. The fabricated nanowire and nanocone array structures outperform existing results with light absorption exceeding 90%.

냉각 시스템으로 Peltier 장치를 사용하여 태양광 패널의 성능 분석

에이드아흐메드 ( Ahmed Fawzy Eid ),홍성구 ( Seonggu Hong ) 한국농공학회 2019 한국농공학회 학술대회초록집 Vol.2019 No.-

One of the main challenges for solar photovoltaic system is temperature rising of solar module, which causes to decrease maximum power voltage (Vmp) of panel. Furthermore, leads to decrease in electrical efficiency, maximum power (Pmax) of solar panel and will cause cells degradation and above lowering of life span expectancy of photovoltaic panels systems. To manage this issue, one of the important methods to improve the solar panel efficiency and keep it at a sufficient level is cooling. There are a lot of methods which are used to cool solar modules such as floating cooling system (FCC), photovoltaic/thermal (PVT) cooled by forced water circulation, solar panel with water immersion cooling technique and thermoelectric device as cooling systems called also Peltier effect device. In this study, two solar panels with different cooling devices were compared with a reference panel (model 3) with respect to its efficiency and performance. A new design of photovoltaic/thermoelectric cooler (PV-TEC) as a cooling system was attached with two fans and two heat sink as one unit, it fixed on the backside of the solar module to cool it from the back (model 2). Another method was a water film (model 1) to improve the electrical module efficiency. A 70 Watts small pump created a water film on the front side of the solar panel to remove the heat from the front. The first results of this study showed the temperatures were 35.5oC, 49 oC and 57 oC for model 1, model 2 and model 3 respectively. The maximum power voltages were 21.36V, 20.69V and 20.05V respectively. Short circuit currents were 5.31A, 5.36A and 5.37A respectively. The ideal output power from modules were 114W, 111W and 107.5W respectively with an improvement in electricity efficiency were 6% and 3.5% for model 1 and model 2 respectively .the cooling system by water film achieved a proper impact on electricity efficiency otherwise the capacity of the thermoelectric cooling unit was not enough to remove the heat from the back sheet of the solar module because of low thermal conductivity of Taddler layer.

Optimal Operation Methods of Protection Devices in Distribution Systems with PV Systems

Byung-Ki Kim,Dae-Seok Rho 한국산학기술학회 2014 SmartCR Vol.4 No.6

This paper deals with the technical problems of protection devices in distribution systems with connected photovoltaic systems by developing a test device of protection coordination for photovoltaic systems. In order to analyze the operational characteristics of the protection devices in a distribution system connected with photovoltaic systems, in which bi-directional power flow could be supplied, this paper develops a test device that is composed of a model distribution system, protection device, and model PV system. By performing a simulation for operational characteristics of the protection devices based on the test device, this paper proposes a malfunction mechanism for the protection devices. The simulation results show that this paper is practical and effective for the technical guideline for the PV systems.

A crucial factor affecting the power conversion efficiency of oxide/metal/oxide-based organic photovoltaics: Optical cavity versus transmittance

Lee, Byeong Ryong,Park, Gi Eun,Kim, Yong Woon,Choi, Dong Hoon,Kim, Tae Geun Elsevier 2019 APPLIED ENERGY Vol.235 No.-

<P><B>Abstract</B></P> <P>Considerable effort has been directed at improving the power conversion efficiency of organic photovoltaics, using oxide/metal/oxide multilayers as transparent electrodes, because of their numerous advantages including lower sheet resistance, higher transmittance, and higher flexibility in comparison to typical indium tin oxides. However, to date, most organic photovoltaics based on oxide/metal/oxide electrodes exhibit a lower conversion efficiency than indium tin oxide-based organic photovoltaics, without any clarification. In this investigation, we identify crucial factors that influence the power conversion efficiency of oxide/metal/oxide-based organic photovoltaics to fully exploit the potential of these devices, based on the correlation between the optical cavity and the transmittance. For this purpose, we fabricate five sets ofinverted organic photovoltaics using poly({4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-<I>b</I>:4,5-<I>b</I>′]dithiophene-2,6-diyl}{3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-<I>b</I>]thiophenediyl}) and [6,6]-Phenyl C<SUB>71</SUB> butyric acid methyl ester-based active layers and ZnO/Ag/ZnO electrodes with top ZnO layers of varying thicknesses, with reference organic photovoltaics using indium tin oxides, on both rigid and flexible substrates. The highest power conversion efficiency of 8.71% and 7.53% is obtained from single-junction organic photovoltaics with 40/9/8-nm-thick ZnO/Ag/ZnO electrodes on each substrate, due to strong micro-cavity effects between the top and bottom Ag layers, despite the relatively low transmittance of the electrode. This result is supported by the relation between the electric-field intensity and the transmittance curves of the ZnO/Ag/ZnO/solution-based ZnO/active bulk optical stacks based on simulation results. Furthermore, flexible organic photovoltaics with the ZnO/Ag/ZnO electrodes demonstrate much better performance in mechanical bending tests in comparison to the performance of standard indium tin oxide-based organic photovoltaics, and the previously reported oxide/metal/oxide-based organic photovoltaics.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Structure for organic photovoltaics with ZnO/Ag/ZnO electrodes is optimized. </LI> <LI> Crucial factor dictating power conversion efficiency is identified in these devices. </LI> <LI> High power conversion efficiency (8.71%) is achieved from organic photovoltaics. </LI> <LI> Excellent mechanical flexibility is also observed. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>We display a crucial factor that dictates the power conversion efficiency (PCE) of OMO-based OPVs by investigating the effect of photon fields in the active region and the transmittance of the electrode on the PCE of ZnO/Ag/ZnO-based OPVs with top ZnO layers of varying thicknesses. One of the optimized OPVs exhibit record-high PCE and mechanical flexibility in these devices.</P> <P>[DISPLAY OMISSION]</P>

Compact Slot Antenna Integrated with a Photovoltaic Cell

Ahmed Ali,Heesu Wang,Yeojun Yun,Jaejin Lee,Ikmo Park 한국전자파학회JEES 2020 Journal of Electromagnetic Engineering and Science Vol.20 No.4

This paper presents a compact low-profile slot antenna integrated with a photovoltaic cell. The photovoltaic cell consists of a top metal grid, gallium arsenide substrate, and metallic bottom contact. The metallic bottom contact was used as a ground plane where the slot was etched for resonance. A second substrate was placed under the ground plane, and a 50 Ω microstrip line was printed on its bottom side to excite the slot. A chip inductor was used as a radio frequency (RF) choke in the alternating current blocking circuit to suppress RF current leakage towards the photovoltaic cell. Hence, the proposed antenna has a unique feature of functioning simultaneously as a photovoltaic cell and an antenna. The overall dimensions--25 mm × 31.75 mm × 0.893 mm (0.48o × 0.61o × 0.017o at 5.77 GHz)--of the photovoltaic cell-integrated slot antenna structure can be used effectively with Internet of Things devices.

Enhancement of Light Absorption in Silicon Nanowire Photovoltaic Devices with Dielectric and Metallic Grating Structures

Park, Jin-Sung,Kim, Kyoung-Ho,Hwang, Min-Soo,Zhang, Xing,Lee, Jung Min,Kim, Jungkil,Song, Kyung-Deok,No, You-Shin,Jeong, Kwang-Yong,Cahoon, James F.,Kim, Sun-Kyung,Park, Hong-Gyu American Chemical Society 2017 NANO LETTERS Vol.17 No.12

<P>We report the enhancement of light absorption in Si nanowire photovoltaic devices with one-dimensional dielectric or metallic gratings that are fabricated by a damage-free, precisely aligning, polymer-assisted transfer method. Incorporation of a Si3N4 grating with a Si nanowire effectively enhances the photocurrents for transverse-electric polarized light. The wavelength at which a maximum photo current is generated is readily tuned by adjusting the grating pitch. Moreover, the electrical properties of the nanowire devices are preserved before and after transferring the Si3N4 gratings onto Si nanowires, ensuring that the quality of pristine nanowires is not degraded during the transfer. Furthermore, we demonstrate Si nanowire photovoltaic devices with Ag gratings using the same transfer method. Measurements on the fabricated devices reveal approximately 27.1% enhancement in light absorption compared to that of the same devices without the Ag gratings -without any degradation of electrical properties. We believe that our polymer-assisted transfer method is not limited to the fabrication of grating incorporated nanowire photovoltaic devices but can also be generically applied for the implementation of complex nanoscale structures toward the development of multifunctional optoelectronic devices.</P>