Development of fullerene derivatives with high LUMO level through changes in π-conjugated system shape

2012 ◽  
Vol 84 (4) ◽  
pp. 945-952 ◽  
Author(s):  
Yutaka Matsuo
Keyword(s):  
Solid State ◽  
Current Density ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Open Circuit ◽  
Fullerene Derivative ◽  
Supramolecular Organization ◽  
High Electron ◽  
Organic Thin Film

This article describes a concept for designing fullerene-based electron-accepting materials to obtain high open-circuit voltage (VOC) in organic thin-film photovoltaic devices without an accompanying decrease in short-circuit current density. The keys to this concept are (1) reducing the size of the fullerene π-conjugated system to realize high VOC and (2) shortening the inter-fullerene distance in the solid-state packing structure to achieve high short-circuit current density (JSC), which is made possible by well-designed supramolecular organization or a small organic addend. In this article, two representative examples are discussed. One is 1,4-bis(silylmethyl)[60]fullerene (SIMEF), which forms a columnar fullerene-core array for high electron mobility and undergoes thermal crystallization for good phase separation with the electron-donating material. The other is a 56π-electron fullerene derivative bearing a dihydromethano group, the smallest carbon addend, which does not disrupt fullerene–fullerene contact in the solid state.

Development of New Fullerene-based Electron Acceptors for Efficient Organic Photovoltaic Cells

2012 ◽  
Vol 1390 ◽  
Author(s):  
Yutaka Matsuo
Keyword(s):  
High Performance ◽  
Open Circuit Voltage ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Open Circuit ◽  
Fullerene Derivative ◽  
High Electron ◽  
Organic Thin Film ◽  
Photovoltaic Devices

ABSTRACTThis article describes design of fullerene-based electron-accepting materials to obtain high performance in organic thin-film photovoltaic devices. A 1,4-bis(dimethylphenylsilylmethyl)[60]fullerene gives higher open circuit voltage than 1,2-diadduct because of smaller π-conjugated systems, and enables columnar fullerene-core array for high electron mobility and thermal crystallization for ideal phase separation with electron-donor materials. A 56π-electron fullerene derivative possessing the dihydromethano group as the smallest carbon addend does not disrupt fullerene-fullerene contact in solid state, giving high open-circuit voltage without decreasing of short-circuit current density and fill factor.

IMPROVING STABILITY OF CHLOROPHYLL AS NATURAL DYE FOR DYE-SENSITIZED SOLAR CELLS

2017 ◽  
Vol 80 (1) ◽  
Author(s):  
Zainal Arifin ◽  
Sudjito Soeparman ◽  
Denny Widhiyanuriyawan ◽  
Suyitno Suyitno ◽  
Argatya Tara Setyaji
Keyword(s):  
Current Density ◽  
Open Circuit Voltage ◽  
Short Circuit ◽  
Dye Sensitized Solar Cells ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Open Circuit ◽  
Natural Dyes ◽  
Dye Sensitized ◽  
Sensitized Solar Cells

Natural dyes have attracted much researcher’s attention due to their low-cost production, simple synthesis processes and high natural abundance. However the dye-sensitized solar cells (DSSCs) based natural dyes have higher tendency to degradation. This article reports on the enhancement of performance and stability of dye-sensitized solar cells (DSSCs) using natural dyes. The natural dyes were extracted from papaya leaves by ethanol solvent at a temperature of 50 °C. Then the extracted dyes were isolated and modified into Mg-chlorophyll using column chromatography. Mg-chlorophyll was then synthesized into Fe-chlorophyll to improve stability. The natural dyes were characterized using ultraviolet-visible spectrometry, Fourier transform infrared spectroscopy, and cyclic voltammetry. The performance of DSSCs was tested using a solar simulator. The results showed the open-circuit voltage, the short-circuit current density, and the efficiency of the extracted papaya leaves-based DSSCs to be 325 mV, 0.36 mA/cm2, and 0.07%, respectively. Furthermore, the DSSCs with purified chlorophyll provide high open-circuit voltage of 425 mV and short-circuit current density of 0.45 mA/cm2. The use of Fe-chlorophyll for sensitizing the DSSCs increases the efficiency up to 2.5 times and the stability up to two times. The DSSCs with Fe-chlorophyll dyes provide open-circuit voltage, short-circuit current density, and efficiency of 500 mV, 0.62 mA/cm2, and 0.16%, respectively. Further studies to improve the current density and stability of natural dye-based DSSCs along with an improvement in the anchor between dyes and semiconducting layers are required.

scholarly journals Simulation of a perovskite sandwich solar cell with the p-CZTS / p-CH3NH3PbCI3 / p-CZTS absorber layers

2021 ◽  
Vol 877 (1) ◽  
pp. 012001
Author(s):  
Marwah S Mahmood ◽  
N K Hassan
Keyword(s):  
Solar Cell ◽  
Conversion Efficiency ◽  
Current Density ◽  
Short Circuit ◽  
Perovskite Solar Cells ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Open Circuit ◽  
Current Voltage ◽  
Cell Capacitance

Abstract Perovskite solar cells attract the attention because of their unique properties in photovoltaic cells. Numerical simulation to the structure of Perovskite on p-CZTS/p-CH3NH3PbCI3/p-CZTS absorber layers is performed by using a program solar cell capacitance simulator (SCAPS-1D), with changing absorber layer thickness. The effect of thickness p-CZTS/p-CH3NH3PbCI3/p-CZTS, layers at (3.2μm, 1.8 μm, 1.1 μm) respectively are studied. The obtained results are short circuit current density (Jsc ), open circuit voltage (V oc), fill factor (F. F) and power conversion efficiency (PCE) equal to (28 mA/cm2, 0.83 v, 60.58 % and 14.25 %) respectively at 1.1 μm thickness. Our findings revealed that the dependence of current - voltage characteristics on the thickness of the absorbing layers, an increase in the amount of short circuit current density with an increase in the thickness of the absorption layers and thus led to an increase in the conversion efficiency and improvement of the cell by increasing the thickness of the absorption layers.

CHARACTERISTICS OF PHOSPHORUS-DOPED AMORPHOUS CARBON FILMS GROWN BY R. F. PLASMA-ENHANCED CVD WITH A NOVEL PHOSPHORUS SOLID TARGET

2005 ◽  
Vol 12 (01) ◽  
pp. 19-25 ◽  
Author(s):  
M. RUSOP ◽  
M. ADACHI ◽  
T. SOGA ◽  
T. JIMBO
Keyword(s):  
Solar Cell ◽  
Conversion Efficiency ◽  
Amorphous Carbon ◽  
Current Density ◽  
Fill Factor ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Open Circuit ◽  
Phosphorus Doped

Phosphorus-doped amorphous carbon (n-C:P) films were grown by r. f.-power-assisted plasma-enhanced chemical vapor deposition at room temperature using a novel solid red phosphorus target. The influence of phosphorus doping on material properties of n-C:P based on the results of simultaneous characterization are reported. Moreover, the solar cell properties such as series resistance, short circuit current density, open circuit current voltage, fill factor and conversion efficiency along with the spectral response are reported for the fabricated carbon-based n-C:P/p-Si heterojunction solar cell that was measured by standard measurement technique. The cells performances have been given in the dark I–V rectifying curve and I–V working curve under illumination when exposed to AM 1.5 illumination condition (100 mW/cm 2, 25°C). The maximum of open-circuit voltage (V oc ) and short-circuit current density (J sc ) for the cells are observed to be approximately 236 V and 7.34, mAcm 2 respectively for the n-C:P/p-Si cell grown at lower r. f. power of 100 W. The highest energy conversion efficiency (η) and fill factor (FF) were found to be approximately 0.84% and 49%, respectively. We have observed that the rectifying nature of the heterojunction structures is due to the nature of n-C:P films.

scholarly journals Study The Current Density-Voltage (J-V) Characteristics of α-Fe2O3 Thin Film Prepared by Spray Pyrolysis Technique

2020 ◽  
Vol 25 (1) ◽  
pp. 1-7
Author(s):  
Mohammed Sami Abd ali ◽  
Ahmed Shaker Hussein ◽  
Hayder Mohammed hadi
Keyword(s):  
Current Density ◽  
Fill Factor ◽  
Spray Pyrolysis Technique ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Open Circuit ◽  
Saturation Current ◽  
Conversion Yield ◽  
Current Voltage

ABSTRACT:   In this work was measured characteristics (current - voltage) for the  (fe2o3 )thin films . The characteristics of the current density-voltage(J-V) were calculated at in both dark and light (100 mw/cm2) conditions. The parameters for this research of the photovoltaic samples, that is, were obtained directly from the curves of the resulting characteristics on the basic variables for the solar cell: the short circuit current density  (Jsc‏  ( ‏ , saturation current (Jo ), open-circuit voltage  (Voc) , fill factor ( FF), and efficiency of solar energy conversion (yield) ƞ ,

scholarly journals Effect of the Phosphorus Gettering on Si Heterojunction Solar Cells

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Hyomin Park ◽  
Sung Ju Tark ◽  
Chan Seok Kim ◽  
Sungeun Park ◽  
Young Do Kim ◽  
...  
Keyword(s):  
Solar Cells ◽  
Current Density ◽  
Crystalline Silicon ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Open Circuit ◽  
Solar Simulator ◽  
Heterojunction Solar Cells ◽  
Crystalline Silicon Solar Cells

To improve the efficiency of crystalline silicon solar cells, should be collected the excess carrier as much as possible. Therefore, minimizing the recombination both at the bulk and surface regions is important. Impurities make recombination sites and they are the major reason for recombination. Phosphorus (P) gettering was introduced to reduce metal impurities in the bulk region of Si wafers and then to improve the efficiency of Si heterojunction solar cells fabricated on the wafers. Resistivity of wafers was measured by a four-point probe method. Fill factor of solar cells was measured by a solar simulator. Saturation current and ideality factor were calculated from a dark current density-voltage graph. External quantum efficiency was analyzed to assess the effect of P gettering on the performance of solar cells. Minority bulk lifetime measured by microwave photoconductance decay increases from 368.3 to 660.8 μs. Open-circuit voltage and short-circuit current density increase from 577 to 598 mV and 27.8 to 29.8 mA/cm2, respectively. The efficiency of solar cells increases from 11.9 to 13.4%. P gettering will be feasible to improve the efficiency of Si heterojunction solar cells fabricated on P-doped Si wafers.

Optimum driving energy for achieving balanced open-circuit voltage and short-circuit current density in organic bulk heterojunction solar cells

2018 ◽  
Vol 20 (47) ◽  
pp. 29866-29875 ◽  
Author(s):  
Wenchao Yang ◽  
Yao Yao ◽  
Pengfei Guo ◽  
Haibin Sun ◽  
Yongsong Luo
Keyword(s):  
Current Density ◽  
Open Circuit Voltage ◽  
Bulk Heterojunction ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Open Circuit ◽  
Model Calculations ◽  
Heterojunction Solar Cells ◽  
Device Model

Device model calculations show that balanced Jsc and Voc can be achieved at an optimum driving energy of 0.2 eV.

Effect of Assets of Silicon Film Passivation Layer on the Performance of Silicon Nanowire Solar Cells

2014 ◽  
Vol 633-634 ◽  
pp. 509-512
Author(s):  
Ping Yang ◽  
Xiang Bo Zeng ◽  
Xiao Dong Zhang ◽  
Zhan Guo Wang
Keyword(s):  
Solar Cell ◽  
Current Density ◽  
Open Circuit Voltage ◽  
Short Circuit ◽  
Silicon Film ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Open Circuit ◽  
Passivation Layer ◽  
Hydrogen Dilution

Silicon film as a surface passivation layer is reported to reduce surface recombination on silicon nanowires (SiNWs) and thus enable to improve SiNW solar cell (SC) performance. A question yet to be answered regards the link between the silicon film assets and the solar cell performances. We investigated the effect of the properties of silicon films on the SiNWs SC performances by adjusting hydrogen dilution. Our results showed that the open-circuit voltage (Voc) and short-circuit current density (Jsc) of SiNWs SC increase until hydrogen dilution 10 and then decrease. An open-circuit voltage of 0.397 V and short-circuit current density of 18.42 mA/cm2 are achieved at optimized hydrogen dilution. Based on the analysis of silicon film properties we proposed that the increase of defect density with hydrogen dilution was the main cause for the deterioration of SiNWs SC performance.

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