• Title/Summary/Keyword: Solar conversion efficiency

Search Result 856, Processing Time 0.028 seconds

Preparation of Al2O3-coated TiO2 Electrode for Recombination Blocking of Photoelectron in Dye-Sensitized Solar Cells (염료감응형 태양전지의 광전자 재결합 방지를 위한 Al2O3 코팅 TiO2 전극 제조)

  • Hwang, Kyung-Jun;Yoo, Seung-Joon;Jung, Sung-Hoon;Kim, Sun-Il;Lee, Jae-Wook
    • Applied Chemistry for Engineering
    • /
    • v.21 no.2
    • /
    • pp.162-168
    • /
    • 2010
  • To increase the energy conversion efficiency of dye sensitized solar cells (DSSCs), it has been widely studied how to effectively transferred the electron generated from the adsorbed dye to the $TiO_{2}$ electrode for avoiding the recombination of injected electrons and iodide ions ($I^-/I_3^-$). For the blocking of the recombination, in this study, $Al_2O_3$-coated $TiO_{2}$ electrode was prepared and applied for DSSCs. In especial, the optimal preparation conditions of $Al_2O_3$ coated onto $TiO_{2}$ porous film was proposed for higher energy conversion efficiency. As a result, the solar cells fabricated from $Al_2O_3$-coated (i.e., particle size of bohemite sol : 100 nm) $TiO_{2}$ electrodes showed superior conversion efficiency (9.0%) compared to the bare $TiO_{2}$ electrodes (7.5%).

The Effect of Sulfurization Temperature on CuIn(Se,S)2 Solar Cells Synthesized by Electrodeposition

  • Kim, Dong-Uk;Yun, Sang-Hwa;Yu, Bong-Yeong
    • Proceedings of the Korean Institute of Surface Engineering Conference
    • /
    • 2014.11a
    • /
    • pp.97-97
    • /
    • 2014
  • The properties of thin film solar cells based on electrodeposited $CuIn(Se,S)_2$ were investigated. The proposed solar cell fabrication method involves a single-step $CuInSe_2$ thin film electrodeposition followed by sulfurization in a tube furnace to form a $CuIn(Se,S)_2$ quaternary phase. A sulfurization temperature of $450-550^{\circ}C$ significantly affected the performance of the $CuIn(Se,S)_2$ thin film solar cell in addition to its composition, grain size and bandgap. Sulfur(S) substituted for selenium(Se) at increasing rates with higher sulfurization temperature, which resulted in an increase in overall band gap of the $CuIn(Se,S)_2$ thin film. The highest conversion efficiency of 3.12% under airmass(AM) 1.5 illumination was obtained from the $500^{\circ}C$-sulfurized solar cell. The highest External Quantum Efficiency(EQE) was also observed at the sulfurization temperature of $500^{\circ}C$.

  • PDF

The Characteristics of a Hydrogenated Amorphous Silicon Semitransparent Solar Cell When Applying n/i Buffer Layers

  • Lee, Da Jung;Yun, Sun Jin;Lee, Seong Hyun;Lim, Jung Wook
    • ETRI Journal
    • /
    • v.35 no.4
    • /
    • pp.730-733
    • /
    • 2013
  • In this work, buffer layers with various conditions are inserted at an n/i interface in hydrogenated amorphous silicon semitransparent solar cells. It is observed that the performance of a solar cell strongly depends on the arrangement and thickness of the buffer layer. When arranging buffer layers with various bandgaps in ascending order from the intrinsic layer to the n layer, a relatively high open circuit voltage and short circuit current are observed. In addition, the fill factors are improved, owing to an enhanced shunt resistance under every instance of the introduced n/i buffer layers. Among the various conditions during the arrangement of the buffer layers, a reverse V shape of the energy bandgap is found to be the most effective for high efficiency, which also exhibits intermediate transmittance among all samples. This is an inspiring result, enabling an independent control of the conversion efficiency and transmittance.

A simple 3-phase inverter topology to improve power conversion efficiency

  • Phan, Dang-Minh;Lee, Hong-Hee
    • Proceedings of the KIPE Conference
    • /
    • 2014.11a
    • /
    • pp.25-26
    • /
    • 2014
  • Renewable energy sources such as wind and solar power are free and can be easily harvested everywhere. However, one of the biggest problems when using this kind of energy source is how to increase the efficiency of power conversion system. This paper introduces a modified 3-phase inverter in order to increase the power conversion efficiency. By adding 3 bi-directional switches at output of the inverter, the current flow back DC source during zero state is prevented to minimize leakage current, so that the efficiency of whole system is increased. The proposed topology also improves the power quality to satisfy the total harmonics distortion (THD) requirement. In order to verify the effectiveness of the proposed topology, simulation results are carried out using Simulink in MATLAB.

  • PDF

Tandem Structured Hot Electron-based Photovoltaic Cell with Double Schottky Barriers

  • Lee, Young Keun;Lee, Hyosun;Park, Jeong Young
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • 2013.08a
    • /
    • pp.310.1-310.1
    • /
    • 2013
  • We show the novel hot electron based-solar energy conversion using tandem structured Schottky diode with double Schottky barriers. In this report, we show the effect of the double Schottky barriers on solar cell performance by enhancing both of internal photoemission and band-to-band excitation. The tandem structured Au/Si diode capped with TiO2 layer as second semiconductor exhibited improved ability for light harvesting. The proposed mechanisms consist of multiple reflections of hot electrons and additional pathway of solar energy conversion due to presence of multiple interfaces between thin gold film and semiconductors. Short-circuit photocurrent measured on the tandem structured Au/Si diodes under illumination of AM1.5 increased by approximately 70% from 3.1% to 5.3% and overall incident photon to electron conversion efficiency (IPCE) was enhanced in visible light, revealing that the concept of the double Schottky barriers have significant potential as novel strategy for light harvesting.

  • PDF

Effect of Selenium Doping on the Performance of Flexible Cu2SnS3(CTS) Thin Film Solar Cells (Mo 유연기판을 이용한 Cu2SnS3 박막 태양전지의 셀레늄 도핑 효과)

  • Lee, In Jae;Jo, Eunae;Jang, Jun Sung;Lee, Byeong Hoon;Lee, Dong Min;Kang, Chang Hyun;Moon, Jong Ha
    • Korean Journal of Materials Research
    • /
    • v.30 no.2
    • /
    • pp.68-73
    • /
    • 2020
  • Due to its favorable optical properties, Cu2SnS3 (CTS) is a promising material for thin film solar cells. Doping, which modifies the absorber properties, is one way to improve the conversion efficiency of CTS solar cells. In this work, CTS solar cells with selenium doping were fabricated on a flexible substrate using sputtering method and the effect of doping on the properties of CTS solar cells was investigated. In XRD analysis, a shift in the CTS peaks can be observed due to the doped selenium. XRF analysis confirmed the different ratios of Cu/Sn and (S+Se)/(Cu+Sn) depending on the amount of selenium doping. Selenium doping can help to lower the chemical potential of sulfur. This effectively reduces the point defects of CTS thin films. Overall improved electrical properties were observed in the CTS solar cell with a small amount of selenium doping, and a notable conversion efficiency of 1.02 % was achieved in the CTS solar cell doped with 1 at% of selenium.

Technical Tasks and Development Current Status of Organic Solar Cells (유기 태양전지의 개발 현황과 기술 과제)

  • Jang, Ji Geun;Park, Byung Min;Lim, Sungkyoo;Chang, Ho Jung
    • Korean Journal of Materials Research
    • /
    • v.24 no.8
    • /
    • pp.434-442
    • /
    • 2014
  • Serious environmental problems have been caused by the greenhouse effect due to carbon dioxide($CO_2$) or nitrogen oxides($NO_x$) generated by the use of fossil fuels, including oil and liquefied natural gas. Many countries, including our own, the United States, those of the European Union and other developed countries around the world; have shown growing interest in clean energy, and have been concentrating on the development of new energy-saving materials and devices. Typical non-fossil-fuel sources include solar cells, wind power, tidal power, nuclear power, and fuel cells. In particular, organic solar cells(OSCs) have relatively low power-conversion efficiency(PCE) in comparison with inorganic(silicon) based solar cells, compound semiconductor solar cells and the CIGS [$Cu(In_{1-x}Ga_x)Se_2$] thin film solar cells. Recently, organic cell efficiencies greater than 10 % have been obtained by means of the development of new organic semiconducting materials, which feature improvements in crystalline properties, as well as in the quantum-dot nano-structure of the active layers. In this paper, a brief overview of solar cells in general is presented. In particular, the current development status of the next-generation OSCs including their operation principle, device-manufacturing processes, and improvements in the PCE are described.

Analysis on Temperature Dependence of Crystalline Silicon Solar Cells with Different Emitter Types for Desert Environment (사막형 결정질 실리콘 태양전지의 에미터 구조에 따른 온도 별 특성 변화 분석)

  • Nam, Yoon Chung;Kim, Soo Min;Kang, Yoonmook;Lee, Hae-Seok;Kim, Donghwan
    • Current Photovoltaic Research
    • /
    • v.2 no.3
    • /
    • pp.135-139
    • /
    • 2014
  • Different power output of solar cells can be observed at high-temperature regions such as desert areas. In this study, performance dependence on operating temperature of crystalline silicon solar cells with different emitter types was analyzed. Based on the light current-voltage (LIV) measurement, temperature coefficients of short-circuit current density ($J_{SC}$), open-circuit voltage ($V_{OC}$), fill factor (FF) and power conversion efficiency were measured and compared for two groups of crystalline silicon solar cells with different emitter types. One group had homogeneously doped (conventional) emitter and another selectively doped (selective) emitter. Varying the operating temperature from 25 to 40, 60, and $80^{\circ}C$, LIV characteristics of the cells were measured and the properties of saturation current densities ($J_0$) were extracted from dark current-voltage (DIV) curve. From the DIV data, effect of temperature on the performance of the solar cells with different electrical structures for the emitter was analyzed. Increasing the temperature, both emitter structures showed a slight increase in $J_{SC}$ and a rapid degradation of $V_{OC}$. FF and power conversion efficiency also decreased with the increasing temperature. The degrees of $J_{SC}$ increase and $V_{OC}$ degradation for two groups were compared and explained. Also, FF change was explained by series and shunt resistances from the LIV data. It was concluded that the degradation of solar cells shows different values at different temperatures depending on the emitter type of solar cells.

A Study on the Performance of 100 W Thermoelectric Power Generation Module for Solar Hot Water System (태양열 온수 시스템에 적용 가능한 100 W급 열전발전 모듈 성능에 관한 연구)

  • Seo, Ho-Young;Lee, Kyung-Won;Yoon, Jeong-Hun;Lee, Soon-Hwan
    • Journal of the Korean Solar Energy Society
    • /
    • v.39 no.1
    • /
    • pp.21-32
    • /
    • 2019
  • Solar hot water system produces hot water using solar energy. If it is not used effectively, overheating occurs during the summer. Therefore, a lot of research is being done to solve this. This study develops thermoelectric power module applicable to solar hot water system. A thermoelectric material can directly convert thermal energy into electrical energy without additional power generation devices. If there is a temperature difference between high and low temperature, it generate power by Seebeck effect. The thermoelectric module generates electricity using temperature differences through the heat exchange of hot and cold water. The water used for cooling is heated and stored as hot water as it passes through the module. It can prevent overheating of Solar hot water system while producing power. The thermoelectric module consists of one absorption and two radiation part. There path is designed in the form of a water jacket. As a result, a temperature of the absorption part was $134.2^{\circ}C$ and the radiation part was $48.6^{\circ}C$. The temperature difference between the absorption and radiation was $85.6^{\circ}C$. Also, The Thermoelectric module produced about 122 W of irradiation at $708W/m^2$. At this time, power generation efficiency was 2.62% and hot water conversion efficiency was 62.46%.

First Principles Study of Mixed Inorganic-Organic Perovskites (HC(NH2)2PbI3-CH3NH3PbBr3) for Photovoltaic Applications

  • Noh, Min Jong
    • Proceeding of EDISON Challenge
    • /
    • 2015.03a
    • /
    • pp.378-381
    • /
    • 2015
  • To produce low cost and efficient photovoltaic cells, inorganic-organic lead halide perovskite materials appear promising for most suitable solar cells owing to their high power conversion efficiency. Most recent research showes that formamidinium lead iodide ($FAPbI_3$) with methylammonium lead bromide ($MAPbBr_3$) improves the power conversion efficiency of the solar cell to more than 18 per cent under a standard illumination because incorporated $MAPbBr_3$ makes $FAPbI_3$-relatively unstable but comparatively narrow band gap-more stable composition. In respect to first principle study, we investigated band gap of $MAPbI_3$, $FAPbI_3$, $MAPbBr_3$, $(FAPbI_3)_{0.89}-(MAPbBr_3)_{0.11}$ and 0.615(eV), 0.466, 1.197, 0.518 respectively through EDISON DFT software. These results emphasize enhancing structure stability is important factor as well as finding narrow band gap.

  • PDF